Thread: 396 build

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Hi first of all im to to ur site so hello from iowa..
So my plans are to hop up my 69 396 in my chevy cst pickup. I want it to scream like a small block hold on to ur pants n throw u in the seat. I want to switch it to an hei distributor and throw a holley on it. Probly try out the lunati 4-7 swap cam. Not sure what duration and lift to use. I want it to run on pump gas and maybe even a little shot of air plane fuel. Ill put a stall converter in it and possibly a 700 r4 for overdrive. Dnt want to go much over 373 gears. Any opinions would be much appreciated
Thanks Wicky.

Welcome to CHR Wicky – I love the Chevy pickups (have a’71 fairly stock 350/350 myself).

You’d be better served if you could provide us a bit more information on your project. Big thing is your budget and how much work you feel comfortable doing yourself.

In that this is a 1969 vehicle we’re looking at an engine that’s 42 years old. If it’s original, it needs to come out and be rebuilt. Pat McCarthy on this site is one of the nation’s premier big block men and he’s an authority on all things pertaining to BBC engines. He can tell you how to build it right or build one for you. Listen carefully to him.

Before going nuts on the engine know that most everyone here will tell you to start at the other end – you said 3:73 and that’s okay with the right tire combination, but if you want to see God when you stomp on the gas, you may want to consider a lower ratio.

You said a 700R4 transmission – might rethink that as well. They can be built to take a lot of horsepower (700 MegaRaptor for about $3000) – but a bullet proof TH400 is a lot less money. That said, if you go to say 4:11’s, the OD on the 700R4 starts to make sense.

Don’t buy intake, cam, carb, headers or anything until you decide how you want the finished product to perform. Then we can help you to “make a list” and you can start to price things out. Be prepared for either some compromise or a bit more time (unless you have a bottomless pit full of money in which case we need to talk!) to get things just as you want them.

One of the exciting bits of hot roddin’ is that we’re never really “done” – just resting a bit before we start the next phase of the project!

As to the 4/7 swap, read the article from February 2009 Hot Rod Magazine at:
Testing Lunati Cams - Hot Rod Magazine
“Clearly, the 4/7 swap has benefits, but whether you'll see them or not in your engine depends on its purpose. Lunati's Humphreys explains, "It really has to do with good heads and intake. With stock castings, I wouldn't expect to see any difference." In fact, he went so far as to say he'd actually lost a little power once when testing the 4/7 swap on a stock 350 Chevy.

Some claim that the firing-order swap should not be used with a dual-plane intake, as the split-plenum arrangement is tuned for the conventional firing order. And while we have not tested that theory, consider this: Ford did not change the intake design when it changed the firing order. Also, Edelbrock's carbureted dual-plane for GM Gen III engines uses the same exact runner configuration as the old small-blocks.

Weighing all the evidence and even the conflicting opinions, here's our conclusion. If you've got a stock daily driver under 5,000 rpm, the 4/7 swap probably isn't worth messing with. If you're into technology and love messing with EFI and want a new toy to play with to justify individual cylinder tuning, by all means get a 4/7 swap and you might find some power. And if you're building a street/strip or maximum effort engine with a single-plane or a tunnel-ram, spend the extra $30 and find yourself a little power and smoothness.”

Again, Welcome and Good Luck with the Truck!
Glenn

Yeah I should have been little more specific than just saying I was going to hop it up. No I plan on pulling and complete rebuild. Ill do all the work my self with exceptions of machine work obviously. As far as budget. I've never built a big block so no idea on average price range. But probly plan on few thousand but really have no idea. And I belong to another website based specifically for chevy trucks and every responce I've got is stay away from the 396 basicaly. Best advice was buy a 454 and throw my rods and crank in it for a 427. Any input on this? Like I said new to nbc so not trying to step on anyones feet just trying to get my ducks in a row.

One more thing I plan on driving this to the car shows and on weekends. So its not like its going to the drag sttip

Originally Posted by wicky

Yeah I should have been little more specific than just saying I was going to hop it up. No I plan on pulling and complete rebuild. Ill do all the work my self with exceptions of machine work obviously. As far as budget. I've never built a big block so no idea on average price range. But probly plan on few thousand but really have no idea. And I belong to another website based specifically for chevy trucks and every responce I've got is stay away from the 396 basicaly. Best advice was buy a 454 and throw my rods and crank in it for a 427. Any input on this? Like I said new to nbc so not trying to step on anyones feet just trying to get my ducks in a row.

i done the 396/402 engine in many ways .guys say a 427 is better and a 454 is better then a 427?? well a 632 will kick the crap out of all them i made them all .its not really hard to think this one out at the end of the day cubic inches win if you can hook it up if not it still fun walking the car side ways threw 3 gears and still beating a guy .the 396/402 can be a great small bbc i have one thats going on Ebay in july gm steel crank .7/16 rods .erson hyd roller cam forged pistons that will have the look of the bbc and sound with good power with very nice parts in it on paper should make hi 460+ HP on good pump gas