Thread: 1971 big block chevy

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I recently purchased a 1971 402(396) chevy big block to replace the one I blew up in my chevelle. Was wondering if I should use a domed piston in new engine or a flat top? Was also wondering how to get more horse power out of this engine, if the bore and stroke are the same as the older model engines why is my horsepower lower? The valves are bigger in the 71 engine than in my 70, so why the horsepower difference? baffled in ohio

steelworker as far as using flat top vs dome pistons its a matter of what kinda compression you are looking to get based on the rest of the way your motor is built...i.e. cam/carb/heads/etc...those are what your compression requirements are based on.

the 402 is just a factory .30 over 396 and right around 1971 is about the time that they started putting more smog equipment on the motors so that could be one reason for the different rating,along with the gross/net hp difference.