A 393 is a 3.85 stroke crank that uses a 5.95 rod and a piston with a 302 pin height. Other rod/piston height combos are out there, but this is the most common it seems. A flat top piston with a 60cc head yields some healthy 12 to 1+ compression ratios depending on valve relief and how high the piston is in the bore.ive got a 351w motor im about to make a 393 stroker out of. what all am i going to need? ive been told ill need a special oil pan and 351 to 302 swap headers or something? so what all little things like that am i going to need?