Another cam question. It looks like I will be pulling out my 71`s 350/270 this winter. This is my plan. Stock heads, will do a 3-angle valve job a little port & polish. 30 over on block, 10 to 1 pistons, double roll timimg chain, cross drill and chanfer crank. Preformer intake, 750 holley. I was thinking about the old chevy cam # 3863151 aka 447 lift 222 dur. Changing out all stock non to spec parts as I go, ( this is where my machine shop past will come in handy)


I will be keeping the stock 400 auto tran. with shift kit. New 2 1/2 exhaust all the way to Dynomax ulta flo`s. This is the same set up I did for my 75 350 camaro and was good. Do you think this will be ok on the vette?

 

I would not use any of the old chevy cams. They are old designs. Not bad cams just old designs. The newer cams have better and more aggresive ramps and produce better power. There has been a lot of technology since that cam you are talking about was designed. Stick with the newer designs like the XE series from Comp Cams or similar grind from some of the other manufacters and you will be better off.

 

I'm pretty happy with the Edelbrock 600cfm carb and the Performer cam, I don't have the high compression pistons yet....
A 750cfm seems a little big for a SB ?

 

You will not get 10:1 without domes if you have the stock "487" heads. Maybe 9:1 with flat tops and those heads. That is a bit low on compression for the "151" cam. You might like the Comp 268H better with that setup.

If you can get the compression up to maybe 10.4 using domes or smaller chambers, you can run the 327/350HP "151" cam or the 350/350HP "962" cam. The "962" is a later design cam that works well in Vettes. I am running it now that way and it is a well balanced combo.

-Mark.

 

Also, check out the Nostalgia Plus, Factory Muscle & Magnum Muscle lines of cams from Comp. From what I can tell, they redesigned/optimized the old school Chevy hi-perf cams. I was going to use one in my cam swap but after much hand-wringing went with an XE solid. Here's a few of em:


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12-106-3: HYDRAULIC: Factory I.D. # 3863151 for, 327 c.i., 1965-68 Factory 350 h.p., 327 c.i., 1967-68, Factory 325 h.p.

Duration at .050: 222
Intake Valve Lift: 0.447
Exhaust Valve Lift: 0.447
Lobe Seperation: 114°
--------------------------------------------------
12-211-2: HYDRAULIC: Magnum Muscle Camshaft for, 327 c.i., 1965-1968, Factory 350 h.p., 327 c.i., 1967-68, Factory 325 h.p.

Duration at .050: 224
Intake Valve Lift: 0.47
Exhaust Valve Lift: 0.47
Lobe Seperation: 110°
--------------------------------------------------
12-671-4: HYDRAULIC: Sound and character of the ever popular GM L79 cam with modern power.

Duration at .050: 229
Intake Valve Lift: 0.468
Exhaust Valve Lift: 0.462
Lobe Seperation: 112°
--------------------------------------------------
12-672-4: HYDRAULIC: Exhaust note of GM 30-30 cam with hydraulic and increased performance.

Duration at .050: 239
Intake Valve Lift: 0.483
Exhaust Valve Lift: 0.477
Lobe Seperation: 112°


Brett

 

THe GM cams are OK, but have low lift numbers and you need high compression. I used a GM L82 cam on my street rod (400 sb, 10:1), but with 1.6 rockers. It had a definite burst of power once you hit 3000 RPM, but idled like a station wagon. It was fun, especially with a 4-speed and 4.11 gears. Joe