Quote:
Originally Posted by Young Pontiac Guy
I really appreciate the comments. Especially not trying to veer me toward a stroker kit.
I would like to run a flat tappet cam. I currently run a 2802 cam in my 670, ported head 400. It was a very budget minded build- just a rering, stock rods/pistons etc. This time looking to do forged piston setup. I am aware that I will likely want more lift than the 2802 offers. Any suggestions are appreciated as to cam, rockers, etc. Like the Crower stuff but open to other suggestions.
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It comes down to personal preference, it's hard to argue with more displacement especially for a heavy street car, but a properly designed 400 combo will put many 455 and strokers to shame.
Do you have any flow data on your current 670's?
You won't want to go much bigger on duration than the 2802 cam with the rear gearing you have planned, the Crower 60243 would be something to consider along with 1.65 rockers. You'll want to keep the overlap in check especially with a manual trans. otherwise you won't have much fun trying to cruise around at lower speeds as it will want to buck.
Personally if you have a decent set of heads already, if it was me I think I'd look at investing the money into a 5 speed overdrive transmission and up the rearend gear to probably 3.90's. The performance gains you'd make with that and the increased fun factor would no doubt exceed the real world performance any head or cam upgrade you could make with a stock 4 speed and 3.08 to 3.23 gears.
Use as light of a piston as you can and for a forged rod the Eagle H-beams are hard to beat for reduced weight and strength.
I learned early on to make these 400's last turning some rpm with the stock cast cranks reducing the weight of the rotating assembly was huge. My first race 400 had 540 gram JE pistons and fairly heavy Crower rods. It hung together pretty well until we started turning over 7000rpm. After that we went to 412 gram JE pistons and aluminum rods, which held up very well even tagging the limiter in the burnout box at 8200rpm probably a few too many times!! We sure surprised the local crowd with their "Pontiac's can't rev" attitude!!LOL
It's your choice of course but I think you might want to consider the 5 speed idea, I've never had a customer regret that investment from a pure driving enjoyment standpoint.
Dave