Thread: Need advice building my first 350 sbc.

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Hey guys I am building a chevy 350 and am wondering what you think about putting the following parts into my motor. Comp Cams 280H hydraulic flat tappet cam, holley 750cfm vacuum secondary carb, and edelbrock performer 2101 intake. I am looking to build around 400 hp, 400ftlb tq. I have a line on these parts cheap. am I on the right path? I am looking to build a high performance street machine.

Good parts cheap is good. However, buying parts isn't the first step. You've got to get some specs first.

A forum member by the moniker "Tech" will chime in on the specifics, if you truly want 400 ponies, you'll heed his advice.

Welcome aboard, nice to see you here too. We've got a couple guys 'round here that are very familiar with the SBC, give'em a chance to stroll along and they be sure to offer you advice in your quest of 400hp.

What is the car that it'll go in? If you're building it up to go fast, have you begun figuring out how you'll stop it?
And since I'm full of questions this morning.. what tranny? What final gear ratio?

And have fun doing the build, if it becomes to much like work, drop the wrenches and find some other way to enjoy life.
Then return when it can be fun again.

Well I typed a reply... and it's not here?? sheesh..
Anyway, Welcome to the club, hope you enjoy your time here.. what's the 400 horses gonna pull?
And if you're getting ready to go fast, have you figured out how you'll stop it?


and now I'm here twice??

Welcome! I'll chime in on your cam choice. You can make a flat tappet cam work if you're careful about your oil choice, very careful with your initial start and break in process, and a bit lucky. You'll have a better chance of a trouble free engine if you go roller cam with the main line oils available today. Most folks shy away from flat tappet cams, and wouldn't take a used flat tappet cam for anything but an art project.

65 impala ss 2 door hardtop. As far as the car goes, i was planning to start with the engine over the winter

Not sure whether i should get new drums or convert to disc brakes. Everything is stock at the moment. Im hoping to be done building the car by end of next year.

Well, the title of the thread has to do with building a 350, so let's get goin'.....
First and foremost, DO NOT BUY ANY PARTS FOR THE PROJECT UNTIL YOU HAVE THE ENTIRE PLAN FOR THE BUILD WRITTEN DOWN ON PAPER AND HAVE THE BLESSINGS OF ALL THE GUYS ON THIS BOARD.
The first thing you will want to do is to strip everything out of the block, including all the oil galley plugs and cam bearings. Then you will want to take the block to an automotive machine shop and have the block deck height measured. From the factory, the block deck height is blueprinted at 9.025", but through the years, one of the owners may have had the block cut to get fresh decks on it so that a certain head gasket would seal. We need to know what the current block deck height is.

Here's a fellow checkin' it with a digital caliper. He will take the measurement he gets there and add the radius of the main bearing bore to it to find the block deck height. He will do this operation on all four corners of the block......
http://jamisonequipment.com/sites/de...s/BHM-24-1.gif

Once more.....DO NOT BUY ANY PARTS.......ANY PARTS......

.

Will do. I should be back from the field on friday so ill give a call around

Thanks tech

Found a place that will strip ,clean, inspect and measure for 200.

Welcome to CHR!

I love the 65 Impala and consider the SS to be in my top five favorite of all time. Are you set on a 350? If I were you, I'd go with a big block to move a two ton car. A lot easier to build 400 plus horsepower when starting with 454 cubic inches. A mild built big block with a 4 speed OD automatic and 3:43 posi would allow you to launch well and cruise comfortably at 70 MPH at around 2,000 RPM with a 27" tire.

A 400 horsepower small block is certainly possible and can be done in in a way that retains decent street manners. It would be easier with a 383 stroker than a stock 350 and if you're going to start from scratch, you should consider the 383 (cubic inches help to move big cars!) Bear in mind that you block will require additional machining if you opt for a 383.

Tech is spot on - get a good machinist to clean and measure the block. You will want to go with a 9.00" stack – Tech is a master here and he will certainly have a few ideas for pistons.

If you stay with iron heads, I’d opt for L31 Vortecs, casting number 12558062 or 10239906. They were used on '96-'99 Chevy trucks with the L31 5700 Vortec engine and are readily available in wrecking yards and on Craigslist / eBay (make sure they’re genuine GM heads – not knock offs!). As an aside, one of the nice things about a reputable wrecking yard is that they’ll guarantee the heads so if your machinist finds a crack you’re not out a ton money for a new one where as Craigslist and ebay purchases are typically guaranteed 30 seconds or 30 feet – whichever comes first.

These heads use rail rockers, so get the rockers with them if you can. These are some of the best flowing production heads that Chevy ever made. A good machine shop will be able to pin the studs, install new seals, and perform a 5-angle valve job. You can buy Comp Cams drop-in beehive valve springs and retainers that complement your cam and you have a great set of heads for well under a grand.

The Vortec heads are 64cc. Use a piston that gives you a static compression ratio between 9.6:1 - 9.8:1. Work with your machinist here. KB (and others) has an offset dish type piston in a D-cup configuration that provides a nice crown to complement the Vortec head configuration. Ask your machinist to cut the block decks to 9.001" for a zero piston deck height and use a 0.039" or 0.040" compressed head gasket. This should allow you to run premium pump gas without detonation. You may need some octane booster depending on the quality of your local petrol supply – in Oregon our gas is crap.

I’d go a bit smaller on the cam. A good cam would be Comp Cams part 12-262-4 or Howards CL112571-12. These are flat tappet cams so you’ll need to pay attention to break-in, but they are both proven performers that won’t break the bank and will give you great performance on the street with a lot of mid-range snap. It will have a bit of a lope but not to the extent that your friends will wonder if you have a flatulating elephant under the hood.

I like the Edelbrock Performer RPM Vortec #7116 intake manifold. This is a Vortec specific manifold that require a square bore (Holley or Edelbrock) carburetor. Stay with a 600 - 650CFM carburetor. I also really like Quadrajet carburetors so the Edelbrock 2116 with a Q-jet would be a good choice as well.

Buy some Hooker 2130-1HKR long tube, equal length headers and route through Flowmaster 40 series mufflers and route all the way out past the rear bumper. I really like ceramic coated for looks, longevity and heat dissipation. I know these are expensive, but they’ll look good for years and perform well. Nothing looks worse than rusty headers. Use good copper gaskets and locking stainless steel bolts – again expensive but leaking exhaust is not only hideous sounding it’s dangerous.

In addition to the above – make sure you get a good new oil pump with a welded or otherwise firmly affixed pickup. Miloden kit with pan, windage tray, bolts, one piece gasket, pump, and pickup is a good investment. Go with a stock 5 quart pan – resist the temptation to go with a deep pan unless you know you’ll have lots of ground clearance.

New lifters – Comp Cams (or comes as a kit with the Howard’s part number above), new timing set – double roller from Summit is fine, new HEI distributor, new water pump, and good gasket set like Felpro.

Others will jump in but this is what came off the top of my head and it should get you 400 plus horsepower and 425 ft/lbs of torque.

Couple more thoughts for you….
Have the machine shop install new cam bearings and new brass freeze plugs. Also have the machinist go over the location of all the galley plugs with you so you know where they are and that they have been properly installed. When you get the block back from the machine shop make sure you really scrub that baby down with hot soapy water. I like Dawn dish washing liquid and water straight from the bottom of the water heater. Put the block on the engine stand. If you don’t have one, buy an inexpensive Harbor Freight four wheel unit and screw a very large cookie sheet to the stand to catch dropped hardware and help keep your floor clean. Dry with compressed air really well. Make sure you have a 55 degree or warmer day and paint the inside of the engine. I use Glyptal. Its $50 a quart from Eastwood – buy the brush on and a quart will do the job real nice (I use the disposable “China” bristle brushes from Harbor Freight). Also paint the exterior at this time too. Let everything dry real well – at least 48 hours.

Stop working when you get tired and you’ll save the headache of having to redo something. I still keep a log sheet on an engine and note everything I’ve done before I quit for the day – of late I’ve started taking pictures with a digital camera then have a visual record as well. It makes it a whole lot easier to ‘take-up-where-I-left-off, especially if there are a couple days between working the engine.

Have fun and let us help!
Glenn

Thanks Glenn, I am not stuck at a 350 as there are many 454's around my area for between 500 and 1000 dollars.
I do happen to have a 350 that came with the car however, and an edelbrock 7101 performer rpm that was donated to me. the 350 I have is casting number 3970014. as far as i can tell (looking on mortec) it is a 68 - 79, im preparing to be underwhelmed as my friend told me it has egr which puts it probably after 73 so most likely its one of those low compression 70s clunkers putting out perhaps 170hp

also there are 2 99' suburbans really close by at a pick and pull. gonna go see them tomorrow. If they are still there, it will only cost me $100 or so for the heads. I really appreciate the help. I know Im in a lot over my head in experience, but not in willingness to work and I've got alot of army buddies that are helping too. This is going to be as much a learning experience for me as a project.
I am waiting on a couple of my mechanic friends to bring their engine hoist over this week hopefully so that I can get the engine over to the machine shop, and get started. In the mean time I've been stripping the paint off the floor pans so I can get an idea as to how much they need to be cut and welded or whether I should replace them entirely. I managed to save some of the interior(seats, rear arm rests and a few others and all my glass is good thankfully.

would i be better with a hydraulic cam? variety of oils in my area isnt the best.