451Mopar
Well-Known Member
I just built a 383. Same pistons, 906 heads, felpro gasket. Pistons 10 thou in the hole. Came out to 8.8 to 1. Comp xe268, 2.14 181 valves, pocket ported. On the dyno it wanted 38 degrees and made 380 hp. That cranking compression doest sound right at all.
Mine had the deck and heads cut, but pistons were still -0.005" below deck. The 906 heads were milled (I think 0.040"), but I used the Fel-Pro 0.039" gasket.
Compression should have been around 9.28:1 as mentioned above.
Had the Crower Compu-Pro Camn#32242 271/284 advertised, 220/230 @ 0.050" duration, 112 lsa, 0.486"/0.494" lift. Built that engine is 1989.
The heads were rebuilt with stock sized valves, hardened exhaust seats and mildly ported.
I ran it with a stock converter, which was OK, but the performance would have been better with a higher stall converter.
I tried the Weiand Stealth dual plane intake, and the Weiand X-Celerator. Back in '89 there was no performer RPM which would have been a better match?
My engine liked 38-degrees total timing also.
Was running with the HP manifolds and a Carter 750 carb. I admit, the carb need tuning work back then.
As I recall above 2,500 RPM the engine pulled pretty good to 6,000 RPM, but I was never impressed with that engine.
I feel like with a stock converter, a smaller cam would have really helped torque and made a better daily driver.
On the other hand, if I was going to use a higher stall converter anyway, then I could have used a larger cam to have better RPM power.
If I did it today, building for daily driver use, I would use the kb pistons with valve reliefs, Edelbrock 75cc E-Street heads, the Hughes Engines SER1620BL-12 cam 216/220 @ 0.050" duration, 0.495"/0.503" lift, and the performer RPM intake. Then likely run a Holley Sniper EFI with timing control to make tuning alot easier, with better start up, and warm up.