Thread: 400 sbc build

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Hi, I have a 1991 Chevy Camaro RS that has a 400 sbc in it. I bought the car with the 400 in it, and I recently came across why its not making a whole lot of power (Its making 210hp,325tq to the wheels.). It appears that the previous owner took the top end of a 305 tbi, (stock 1991 camaro motor) and slapped it ontop of a 400sb. So the heads, cam, intake, and tbi are all designed for a emissions 305 aka junk. I have a budget of $4000 to work with to beef up the motor. Ill have my parts list so far down below along with my power goals. Transmission is a borg warner t5, and yes I know, with my power goals it will go eventually, I have money out of my budget set aside for a t56 swap when that time comes. Rearend is a 10 bolt 7.5, stock on these cars, and its got a eaton trutrac locker in it, it currently runs 9.3 on the 1/8th mile. And I eventually plan to up to a ford 9 inch when that time comes aswell.

Parts List:
Holley Sniper EFI (https://www.summitracing.com/parts/sne-550-511k)
Edelbrock Torker II manifold https://www.summitracing.com/parts/edl-5001)
Brodix Cylinder Heads IK 200 (https://www.summitracing.com/parts/bro-1021001)
Holley EFI Distributor (https://www.summitracing.com/parts/hly-565-100)

apr headstuds, felpro-performance headgaskets, felpro intake gaskets

along with a comp cams 12-250-3, hydraulic flat tappet lifters, roller tip 1.5 rocker arms.

I'm shooting for 450-550hp+ at the flywheel, 400hp+ to the wheels, and I would like to know if this is possible with my parts list, because if it's not then id rather save my money and wait. Nitrous is also an option in my build. Maybe a 100-150 shot? I would have to do further research to find out how to set that up with a holley efi.

Hello Garrett, my name's Richard. I figure that you're probably 19 years old and this is your first foray into hot rodding an automobile. You are at a place in life where all of us on these forums have been before. Some of us were able to finish our firstborn and move on to other projects, while others of us failed somewhere along the way and relegated the project to sit out beside the shed to rust away into oblivion.

There are some main points that will make or break the project, such as money, time, a place to perform work, tools to perform work, continued interest in the project and sticking to the original plan as closely as possible. You will need to make certain that you will continue to want your name on the title of this Camaro and not foresake it for another, sexier model down the road. So, in that vein, you will want to also make sure that what you're starting with is a solid piece, rust-free and never having been in an accident. Drive the car around to several auto body shops, they can tell you pretty quickly if the car has been hit or not, and whether or not it is suffering from terminal cancer (rust). Also, have them identify whether or not it is a "flood" car. Pay 'em a few bucks to look at it.

If you'll tell me the state where you live, so I can look up the elevation of Lakeview, we'll continue.....Also, I'll need to know what fuel is available in your area. What's the highest octane rating at the pump? Do you have E85 available?
.

Welcome to CHR:

Can you tell us a bit about how this car will be driven? Drag race only or street with an occasional ¼ mile blast? Saturday night cruise in or daily driver?

I’m not an EFI guy so I cannot comment on what’s good, bad or indifferent there. I do think that the Sniper is a lot of money.

A couple things that may need some clarifications:

The 400 requires steam holes in the heads. The heads you’ve selected will need to be drilled for such. Make sure you use a 400 head gasket.

In my opinion, the cam you’ve selected is a bad choice if you plan on driving the car on the street. I’d also recommend that you use a roller setup. Yes, it’s more expensive but flat tappet cams require exact break in and often fail within the first hour of run time if not seasoned properly. As a side note - if you’re on a budget, the extra money spent for roller tips would be better spent elsewhere.

The Torker II is not a good choice for street use as it’s a real dog under 2500 rpm.

And as you’ve already mentioned, the transmission (not to mention clutch) and rear end are marginal in your current configuration and will fail immediately with 450 horsepower applied – especially with sticky tires.

Would you be interested in pulling the engine out and using your $4k for complete rebuild? With a .030 bore and 18cc dish pistons in a zero deck and a .040 gasket you’d be around 9.8:1 with 64cc heads. You need to deck the block to zero as the 400's all tended to have pistons that sat down between .060 and .075 - crazy - I know, but they were low compression engines. Buy a pair of these heads:
https://sdparts.com/i-23901396-sdpc-...g-upgrade.html

For about $1K they are some of the best heads anywhere. SD really knows their stuff and they have properly reworked this Vortec to allow a higher lift. You’ll still need to drill the heads for steam – another $100 at the machine shop to have it done correctly.

Roller cam – stay in the 225-230 duration (at .050") range with a .0500" - .510" lift like this Howards (kit including retrofit lifters) https://www.summitracing.com/parts/h...5-10/overview/ Remember to use the proper pushrods.

Use an Edelbrock Performer RPM or a Weiand Speed Warrior with a 750 CFM carburetor.

Regards,
Glenn

Welcome aboard Garrett3698, nice to see you here.
I see a couple of the folks have already given some great advice, and I'd like to echo a couple comments, the intake is a poor selection for the reason already stated, unless you're primarily racing the car? And again, a flat tappet cam with todays oils could be a recipe for disaster, again for the reasons stated.

I would urge you to consider spending some of your budget in stopping the car. Stopping can be more important than trying to go faster! Better brake pads, rotors etc. etc. If you get the car going fast enough, you may discover the limitations of the stock parts and that could end badly.

Hey Tech - looks like Lake View New York is up near Buffalo? - Lakeview NY is on Long Island - elevation 39'. Guess we'll wait for OP to respond.

....................

Originally Posted by glennsexton

Welcome to CHR:

Can you tell us a bit about how this car will be driven? Drag race only or street with an occasional ¼ mile blast? Saturday night cruise in or daily driver?

I’m not an EFI guy so I cannot comment on what’s good, bad or indifferent there. I do think that the Sniper is a lot of money.

A couple things that may need some clarifications:

The 400 requires steam holes in the heads. The heads you’ve selected will need to be drilled for such. Make sure you use a 400 head gasket.

In my opinion, the cam you’ve selected is a bad choice if you plan on driving the car on the street. I’d also recommend that you use a roller setup. Yes, it’s more expensive but flat tappet cams require exact break in and often fail within the first hour of run time if not seasoned properly. As a side note - if you’re on a budget, the extra money spent for roller tips would be better spent elsewhere.

The Torker II is not a good choice for street use as it’s a real dog under 2500 rpm.

And as you’ve already mentioned, the transmission (not to mention clutch) and rear end are marginal in your current configuration and will fail immediately with 450 horsepower applied – especially with sticky tires.

Would you be interested in pulling the engine out and using your $4k for complete rebuild? With a .030 bore and 18cc dish pistons in a zero deck and a .040 gasket you’d be around 9.8:1 with 64cc heads. You need to deck the block to zero as the 400's all tended to have pistons that sat down between .060 and .075 - crazy - I know, but they were low compression engines. Buy a pair of these heads:
https://sdparts.com/i-23901396-sdpc-...g-upgrade.html

For about $1K they are some of the best heads anywhere. SD really knows their stuff and they have properly reworked this Vortec to allow a higher lift. You’ll still need to drill the heads for steam – another $100 at the machine shop to have it done correctly.

Roller cam – stay in the 225-230 duration (at .050") range with a .0500" - .510" lift like this Howards (kit including retrofit lifters) https://www.summitracing.com/parts/h...5-10/overview/ Remember to use the proper pushrods.

Use an Edelbrock Performer RPM or a Weiand Speed Warrior with a 750 CFM carburetor.

Regards,
Glenn

Steam holes I am already fully aware of, and the gaskets I have picked out do have the steam holes, and I have a machine shop a few miles away from where I live. I already have the cam, lifters, pushrods, and roller tip rocker arms, bought them from a friend who put the cam setup in an engine for a break in, then decided to go with a bigger cam, so technically they are already broken in. But im open to all suggestions and everything will depend on my budget, im not an expert hence why I am posting on here. My plans with the car are street/strip, mainly daily driving it in nice weather, (sunny and dry, I never drive it in rain.) and occasionally taking it to my local 1/8th mile drag strip for some drag racing, non competitive, but still drag racing. Like I said previously, I do plan on doing a t56 swap after my t5 gives out, and the rear end, its slightly built up but I know I will have to eventually get a ford 9 inch or equivalent. I plan to do most if not all the labor (besides machining) by myself.

Originally Posted by glennsexton

Hey Tech - looks like Lake View New York is up near Buffalo? - Lakeview NY is on Long Island - elevation 39'. Guess we'll wait for OP to respond.

Lakeview, near Buffalo NY. Elevation is 600′

Originally Posted by techinspector1

Hello Garrett, my name's Richard. I figure that you're probably 19 years old and this is your first foray into hot rodding an automobile. You are at a place in life where all of us on these forums have been before. Some of us were able to finish our firstborn and move on to other projects, while others of us failed somewhere along the way and relegated the project to sit out beside the shed to rust away into oblivion.

There are some main points that will make or break the project, such as money, time, a place to perform work, tools to perform work, continued interest in the project and sticking to the original plan as closely as possible. You will need to make certain that you will continue to want your name on the title of this Camaro and not foresake it for another, sexier model down the road. So, in that vein, you will want to also make sure that what you're starting with is a solid piece, rust-free and never having been in an accident. Drive the car around to several auto body shops, they can tell you pretty quickly if the car has been hit or not, and whether or not it is suffering from terminal cancer (rust). Also, have them identify whether or not it is a "flood" car. Pay 'em a few bucks to look at it.

If you'll tell me the state where you live, so I can look up the elevation of Lakeview, we'll continue.....Also, I'll need to know what fuel is available in your area. What's the highest octane rating at the pump? Do you have E85 available?
.

This car is super solid, no rust anywhere besides a small bit forming on the rear fender, which will be taken care of as soon as it comes out of storage this spring/summer, it was originally from Missouri (ran a title check) and came to buffalo around 2009, where the former owners had it since, and kept it in a garage every winter. This car is my low budget dream car, so I plan on having it for a very very long time, I have tons of ideas for the car, and just recently was able to save some money and have those ideas within reach. I plan on doing most of the work my self, in my garage, ive torn apart small block chevys before so I have a good understanding on the ins and outs of a stock sbc. But I am no expert so thats why I am on here. And 93 octane is the most common, I run it in my camaro (it pings if I run anything lower) and also in my Focus ST (turbocharged, more power with the higher octane). E85 is also around but is not very common, but I would be open to doing an E85 build if it had a significant gain in power over a 93 oct build.

Welcome aboard, there's a lot of great engine builders on here who know how to make an engine run fast, not just sound fast.On a side note I like the 3rd gen Camaro. Their popping up on here more and more. I got an 82 z28, the exhaust is a bit of a challenge on these cars. Make sure you get some frame connectors for body strength as well.

Originally Posted by 53 Chevy5

Welcome aboard, there's a lot of great engine builders on here who know how to make an engine run fast, not just sound fast.On a side note I like the 3rd gen Camaro. Their popping up on here more and more. I got an 82 z28, the exhaust is a bit of a challenge on these cars. Make sure you get some frame connectors for body strength as well.

Yeah I plan to run it straight piped right out the side so I wont have to mess around with a restrictive exhaust system, and I actually have UMI Subframe connectors sitting in the passenger seat of the car, waiting to be put on once I get her out of storage!

Before I get too involved in this, how would you feel about buying a donor, a whole, running 2WD Chevy pickup or 2WD SUV with an LS motor and use all the mechanicals out of it to transfer into your Camaro. With a turbo, you could make 750 horsepower on E85 with all-stock mechanicals. You'd have to tweak the computer and other EFI parts, but the inside of the motor could remain stock. I've seen late model, low miles trucks and SUV's that have been involved in an accident sell for $1200-$1500. You could use the front and rear clips and have power disc brakes and a strong differential with all fresh front end and R&P. Once you had used everything out of the donor that you wanted, you would still have the interior, exterior sheet metal and glass to sell off for money to reduce the cost of the donor. You could even use the wheels and tires off the donor. What do you think about this approach ?
.

duplicate
.

Originally Posted by garrett3698

Hi, I have a 1991 Chevy Camaro RS that has a 400 sbc in it. I bought the car with the 400 in it, and I recently came across why its not making a whole lot of power (Its making 210hp,325tq to the wheels.). It appears that the previous owner took the top end of a 305 tbi, (stock 1991 camaro motor) and slapped it ontop of a 400sb. So the heads, cam, intake, and tbi are all designed for a emissions 305 aka junk.

This sounds bogus. Have you run the numbers on the block?
http://www.crankshaftcoalition.com/w...lock_codes.jpg

Originally Posted by garrett3698

I have a budget of $4000 to work with to beef up the motor.

At the rate of $10 per horsepower, I doubt this will be enough. Plan on spending $1000 just for squaring up the block, boring, honing, working the main bearing bore, cutting the decks to the stack of parts you will use (zero deck), etc. And that's if the 400 bore is stock. If it's already bored +0.030", you will likely want to find another block. A +0.060" Chevy small block generally leaves some part of the cylinders too thin to cancel harmonics that are set up by the piston rings skidding up and down the bore. (You may have thought that the rings slide smoothly up and down the bore.....NO Bunkie, they skid.) If left uncancelled, these harmonics will separate the cooling water on the other side of the jacket into water and air bubbles. The air bubbles then cling to the cylinder walls on the water jacket side of the cylinder and prevent cooling water from getting to the cylinder to carry away heat. The result is an overheating motor that you cannot cure. The block is junk unless it's a numbers-matching restoration and you want to sleeve the cylinders.

Originally Posted by garrett3698

I'll have my parts list so far down below along with my power goals. Transmission is a borg warner t5, and yes I know, with my power goals it will go eventually, I have money out of my budget set aside for a t56 swap when that time comes. Rearend is a 10 bolt 7.5, stock on these cars, and its got a eaton trutrac locker in it, it currently runs 9.3 on the 1/8th mile. And I eventually plan to up to a ford 9 inch when that time comes as well.

And I'm sure you know that this will be another $1500+ for the differential, new control arm bushings and shocks, and you still have drum brakes.

Originally Posted by garrett3698

Holley Sniper EFI ([URL="https://www.summitracing.com/parts/sne-550-511k"]

Pretty pricey, but if it works, great. Says it will support 650 hp, so would support anything naturally aspirated. If you were to use a turbo, you'd have to cut back on the boost to limit horsepower to around 650.

Originally Posted by garrett3698

Edelbrock Torker II manifold https://www.summitracing.com/parts/edl-5001) .

Use Edelbrock 7101 or Weiand 8150. Do not use an air gap intake manifold. Experiment with spacers. You would leave 20-30 hp on the table with the shorter Torker manifold.

Originally Posted by garrett3698

Brodix Cylinder Heads IK 200 (https://www.summitracing.com/parts/bro-1021001) .

These are OK heads, but would not be my choice. Profiler 195's would support 500-550 naturally aspirated and they're less money than the Brodix units, about $1200 for a set complete.
https://www.profilerperformance.com/...ree-heads.html

Originally Posted by garrett3698

Holley EFI Distributor (https://www.summitracing.com/parts/hly-565-100) .

I know nothing about EFI, so you're on your own here. Just make sure it will retard the spark for boost or juice.

Originally Posted by garrett3698

apr headstuds, felpro-performance headgaskets, felpro intake gaskets .

Not apr, ARP. Studs will not be necessary and are a genuine pain in the ass when it comes time to pull a head with the motor in the car. The heater/AC assy is in the way on the passenger side and the brake booster is in the way on the driver's side. Just use a quality head bolt. Use Fel-Pro 1014 head gaskets, 0.039" compressed thickness. Together with a ZERO deck, these will give you a 0.039" squish/quench, eliminating detonation and pre-ignition. Here's a pretty decent article explaining the two....
https://en.wikipedia.org/wiki/Engine_knocking

Originally Posted by garrett3698

along with a comp cams 12-250-3, hydraulic flat tappet lifters, roller tip 1.5 rocker arms.

If this cam has been run before in another motor, then it's junk except for running in the motor where it was run before, with new lifters. Don't ever run a flat tappet cam in two different motors. It's not a good idea. There are other places to save money. I don't like these aggressive grinds on the street either. They're very noisy and put undue stress on the valvetrain for a street motor. Now, if you are 100% drag racing the motor and are looking for every single horsepower in a competition venue, then yes, go for it. For the street, I would prefer to pull back on the Hydraulic Index (subtract 0.050" duration from advertised duration to find H.I. For instance, 230 subtracted from 290 equals 60) and use a milder grind for the longevity of the motor. Harvey Crane came up with this way of looking at the rate of lift of a cam lobe (H.I.). He used an H.I. of 62 for years and years and built an empire on Crane Cams, because they performed well, were quiet in operation and lasted a long time.

In recent years, other cam grinders have begun to use faster ramps to get a little more horsepower from the lobe design. While this works, it also puts additional stress into the valvetrain. An H.I. of 65 to 75 would be a very slow and easy ramp, something generally used by cam grinders like Melling for a bone stock rebuild where you want to get a lot of life from the cam with dead-smooth and very quiet operation. Other grinders will use an H.I. of maybe 40 to 50 H.I., which works the lobe and all other valvetrain parts very hard. This generally results in a very noisy operation as well. I like to use a range of 52 to 62 in a street motor for relatively quiet operation, good power and valvetrain longevity. Everything is a compromise.

Trying to use a flat tappet cam in today's world is just foolish. Here's a tutorial that I wrote for another forum several years ago, when we started fragging cams as a result of the oil manufacturers pulling extreme pressure lubricants from motor oils.
http://www.crankshaftcoalition.com/w...ips_and_tricks

Match up a good hydraulic roller cam to your static compression ratio and operating range and forget it. If you are wanting some lope from the cam, then you will have to raise the static compression ratio up to match up with the cam. Low static compression ratio, short cam. High static compression ratio, long cam. When we get a little further along with putting this build together on paper, I'll help you to choose a cam and show you why I used what I did. Of course, you have the option of calling up the cam grinders and talking to their engineering department for a recommendation after you have all the other parts and systems of the build nailed down. The LAST part you buy for the build should be the cam and lifters. I like Howards roller hydraulic cams and Howards roller hydraulic lifters, bought as a kit together. (CL in front of the part number). Always....ALWAYS purchase your lifters from the grinder who supplies your cam. "White box" lifters of unknown origin ARE NOT a bargain.

I would not use the roller tip rockers, particularly if they are CompCams Magnum units, cast iron with the ball socket fulcrum. In my opinion, those are junk. If you want to use roller rockers, use Scorpion aluminum roller rockers. They're affordable and of good quality. The power gain and oil temperature reduction with roller rockers is in the fulcrum, not the tip. Famed cam grinder Racer Brown showed that those tiny little rollers are too small to effect a mechanical couple with the valve stem tip anyway. They just skid across in most cases. I am of the opinion that the rocker arm manufacturers got it bass-ackwards. The best design, in my opinion, would be a roller fulcrum with a conventional tip. Racer Brown showed how a conventional tip can be rolled on the valve stem tip without tearing a thin cigarette paper, so that crappy little roller on the tip is just a joke in most cases.

Originally Posted by garrett3698

I'm shooting for 450-550hp+ at the flywheel, 400hp+ to the wheels, and I would like to know if this is possible with my parts list, because if it's not then id rather save my money and wait.

Not with your original plan. Start with your fuel choice and build from there.

Originally Posted by garrett3698

Nitrous is also an option in my build. Maybe a 100-150 shot? I would have to do further research to find out how to set that up with a holley efi.

I would use a plate system between the EFI and intake manifold. Building a 500 hp naturally aspirated motor with a 150 shot would make sense. Plan on forged pistons and increased clearances on bearings and rings. Also plan on a way to reduce ignition timing when you goose the juice.

And in closing, it has always been my recommendation to begin work at the rear of the vehicle and work to the front, with the cam and torque converter being your last two purchases. Buying a cam and then building a motor around it is not the hot tip.

.

Originally Posted by techinspector1

This sounds bogus. Have you run the numbers on the block?
http://www.crankshaftcoalition.com/w...lock_codes.jpg


At the rate of $10 per horsepower, I doubt this will be enough. Plan on spending $1000 just for squaring up the block, boring, honing, working the main bearing bore, cutting the decks to the stack of parts you will use, etc. And that's if the 400 bore is stock. If it's already bored +0.030", you will likely want to find another block. A +0.060" Chevy small block generally leaves some part of the cylinders too thin to cancel harmonics that are set up by the piston rings skidding up and down the bore. (You may have thought that the rings slide smoothly up and down the bore.....NO.) If left uncancelled, these harmonics will separate the cooling water on the other side of the jacket into water and air bubbles. The air bubbles then cling to the cylinder walls on the water jacket side of the cylinder and prevent cooling water getting to the cylinder to carry away heat. The result is an overheating motor that you cannot cure. The block is junk.


And I'm sure you know that this will be another $1500+ for the differential, new control arm bushings and shocks.


Pretty pricey, but if it works, great. Says it will support 650 hp, so would support anything naturally aspirated. If you were to use a turbo, you'd have to cut back on the boost.


Use Edelbrock 7101 or Weiand 8150. Do not use an air gap intake manifold. Experiment with spacers. You would leave 30-40 hp on the table with the shorter Torker manifold.


These are OK heads, but would not be my choice. Profiler 195's would support 500-550 naturally aspirated and they're less money than the Brodix units, about $1200 for a set complete.
https://www.profilerperformance.com/...ree-heads.html


I know nothing about EFI, so you're on your own here.


Not apr, ARP. Studs will not be necessary and are a genuine pain in the ass when it comes time to pull a head with the motor in the car. The heater assy is in the way on the passenger side and the brake booster is in the way on the driver's side. Just use a quality head bolt. Use Fel-Pro 1014 head gaskets, 0.039" compressed thickness. Together with a ZERO deck, these will give you a 0.039" squish/quench, eliminating detonation and pre-ignition. Here's a pretty decent article explaining the two....
https://en.wikipedia.org/wiki/Engine_knocking


If this cam has been run before in another motor, then it's junk except for running in the motor where it was run before, with new lifters. Don't ever run a flat tappet cam in two different motors. It's not a good idea. There are other places to save money. I don't like these aggressive grinds on the street either. They're very noisy and put undue stress on the valvetrain for a street motor. Now, if you are 100% drag racing the motor and are looking for every single horsepower in a competition venue, then yes, go for it. For the street, I would prefer to pull back on the Hydraulic Index (subtract 0.050" duration from advertised duration to find H.I. For instance, 230 subtracted from 290 equals 60) and use a milder grind for the longevity of the motor. Harvey Crane came up with this way of looking at the rate of lift of a cam lobe (H.I.). He used 62 for years and years and built an empire on Crane Cams, because they performed well, were quiet in operation and lasted a long time. In recent years, other cam grinders have begun to use faster ramps to get a little more horsepower from the lobe design. While this works, it also puts additional stress into the valvetrain. An H.I. of 65 to 75 would be a very slow and easy ramp, something generally used by cam grinders like Melling for a bone stock rebuild where you want to get a lot of life from the cam with dead-smooth and very quiet operation. Other grinders will use an H.I. of maybe 40 to 50 H.I., which works the lobe and all other valvetrain parts very hard. This generally results in a very noisy operation as well. I like to use a range of 52 to 62 in a street motor for relatively quiet operation and good power. Everything is a compromise.

Trying to use a flat tappet cam in today's world is just foolish. Here's a tutorial that I wrote for another forum several years ago, when we started fragging cams as a result of the oil manufacturers pulling extreme pressure lubricants from motor oils.
http://www.crankshaftcoalition.com/w...ips_and_tricks

Match up a good hydraulic roller cam to your static compression ratio and operating range and forget it. If you are wanting some lope from the cam, then you will have to raise the static compression ratio up to match up with the cam. Low static compression ratio, short cam. High static compression ratio, long cam. When we get a little further along with putting this build together on paper, I'll help you to choose a cam and show you why I used what I did. Of course, you have the option of calling up the cam grinders and talking to their engineering department for a recommendation after you have all the other parts and systems of the build nailed down. The LAST part you buy for the build should be the cam and lifters. I like Howards roller hydraulic cams and Howards roller hydraulic lifters, bought as a kit together. (CL in front of the part number).

I would not use the roller tip rockers, particularly if they are CompCams Magnum units, with the ball socket fulcrum. In my opinion, those are junk. If you want to use roller rockers, use Scorpion aluminum roller rockers. They're affordable and of good quality. The power gain and oil temperature reduction with roller rockers is in the fulcrum, not the tip. Famed cam grinder Racer Brown showed that those tiny little rollers are too small to effect a mechanical couple with the valve stem tip anyway. They just skid across in most cases. I am of the opinion that the rocker arm manufacturers got it bass-ackwards. The best design, in my opinion, would be a roller fulcrum with a conventional tip. Racer Brown showed how they can be rolled on the valve stem tip without tearing a thin cigarette paper, so that crappy little roller on the tip is just a joke.


Not with your original plan. Start with your fuel choice and build from there.


I would use a plate system between the EFI and intake manifold. Building a 500 hp naturally aspirated motor with a 150 shot would make sense. Plan on forged pistons and increased clearances on bearings and rings.

.

I appreciate the the input and I will be further looking into this build based on your suggestions, one thing I did want to say though, it may sound bogus but the block casting number is 330817 which is a 70s-80s 400CID small block chevy, the number on the heads, manifold, and tbi all come back to a emissions 305 sbc.