Overkill on a Stock Bottom End?

[Injectedcutty]

As said above...single plane intakes really only benefit from 3000rpm and above, which defeats the purpose of a street car that has good idle manners and vacuum.

You would benefit much more from a decent dual plane such as an eddy air gap. I had a weiand stealth when my 355 was carbed, stock bottom end...but the intake was good from 1500-6500rpm. Ran a 650 street demon carb, cast heads with 2.02/1.60 valves, decent headers, etc. That motor had plenty of grunt outta the hole and pulled hard to 7k without issue.

Note...i was running a summit 1107 cam which was 232/242 duration, .488/.510 lift which was too big for the converter to match....but i drove it daily and didn't want it revving high. However, once the motor hit the cam powerband around 3400rpm, it would stick me in the seat!

 

[motorheadmike]

Huh, the prices on these things have really come down. In short, if you don't get the compression up the top end will feel really lazy on the street. You can pull the heads off your engine, see where the pistons sit in/out of the deck and determine what your approximate static CR is going to be, cam timing will dictate your dynamic CR.

 

[383_GrandPrix]

To get a camshaft with enough lift/duration to really take advantage of all the flow available in those heads you'd be looking at a power band way above anything a sane person (I know few of us are, but still) would consider streetable. Those heads are rated to accept a cam with up to .700" lift, a cam that big is for race purposes only. That's not to say that you can't use a smaller cam with those heads, it's just that what's the point then? I'd say find a smaller head, something 180, 185, 190 intake runner size would be more then enough to make a fun street car.

 

[lilbowtie]

You can find out what your rear end is - see where the engine presently stalls or spins the tires - intake - carb - cyl head casting #. What do you want to do and what are willing to change. My stock block 350 makes a lot of HP w/o the big bucks.

 

[Bar50]

You might consider a Vortec top end and maybe even a hydraulic roller cam....

 

[64nailhead]

You might consider a Vortec top end and maybe even a hydraulic roller cam....

I agree with this ^^^^ considering you originally mentioned alot of street driving daily. 375-425HP is not difficult with a set of Vortecs, the correct cam, dual plane intake and decent set of headers.

Those 215 cc heads you linked would be great on a 383 that's running in excess of 6300 rpms, but on your 350 you will not find them useful if you want to put in a cam that is streetable.

What's your budget? I'd assume it's at least $1600 since you linked the Skip White kit. $2000 will get you everything you need to make 400+ and maintain some street manners, and you might be able to do it a little cheaper. You really need to see what pistons you have and how far down in the hole they are (rebuilder pistons or stock replacements in terms of compression height.)

 

[MalibuBrandon]

Really great advice guys, exactly the input I'm looking for. Yes, around $2000-2500 is my budget when all is said and done, and I'm hoping to save some of that toward a posi rear end swap. Possibly a 10bolt from a GN or 442, or a 68-72 A body 12 bolt, as Ive read that both are direct bolt in swaps (except the 12 bolt will require 6" backspaced wheels)

 

[lilbowtie]

Since the motor is coming apart, figure out what you got. Go from there for your build up. Match up all your components and don't just throw parts at it or You will be disappointed and broke.

I have to agree with this - we have no idea where your at or where you want to go.