I have a '72 351C 2V I am putting in a 56 ford sedan. After some research on the motor specs, I saw the big HP drop on these motors between '71 and '72. One of the changes the factory made was retarding the cam timing 4 deg. I am installing a double roller chain with different degree options. I know I can put the timing back to the '71 spec, but what would happen if I advanced the timing 4 deg.? That would be an 8 deg. difference from the 72 spec. Is this benificial, or a bad idea? I will be running a performer-ish cam, dble roller timing chain, performer intake and 600 carb, Gm style HEI ignition. Bottom end and heads are stock Thanks.