Manifolds aren't governors, they don't set rpm------------camshafts and valve train equipment is what sets rpm--but then you must have equipment to let the motor survive at those rpms--manifolds have to do with driveability, altho they can (and will ) affect the hp/torque curves somewhat----------Horsepower is result of $$$$$$$$$$$$$$$$$


If you want to make enough HP to break a 2 bolt block get your main / rod bolts at auto zone or Lowes from one of those drawers---------Lowes must be best because they sponser Jimmy