Join Date: Mar 2000
Location: Newton, IA U.S.A.
My Big Block Chevy book says these are 65-76 345,360,390 HP 396,454. As far as I'm aware, the 396 never had flat tops. My 396 has .182"domes and they are 10.25 to 1 comp. They actually say that open chamber heads increase your horsepower. The pistons do not shroud the valves like closed chamber. Allowing more air intake increases hp. I would suggest a Comp hydraulic cam such as the 268 to 274 Extreme Energy, depending on what gear ratio you have, and trans, stall converter, comp., etc... These cams give you more vacuum than others on the market, and they will give you a rumbly idle, but can still use your stock torque converter. Use a good dual plane intake manifold, aluminum preferably. I would recommend a 750 cfm carb. I would stay vacuum secondary though, more streetable/ecomical. These engines like their fuel!