If you are sure you want to use the original block here is my recipe.Do not stroke the engine.Forget the 516's.New pistons 9.5 to 1.A set of 915's with the 2.08 and 1.75 exh valves (doesn't need big valves) w/bowl job and port match.Performer RPM with a 750 of your choice.Lunati 60303 and 1 7/8 headers.Should make 1+ h.p per cubic inch and have some great torque too. Enough engine to run in the 12's and won't break the bank either.