[FED 387]

To answer your question YES you can use aftermarket parts-----Which parts will be accepted I do not know!!!!!! You will have to get an OK from NHRA Tech Dept as to which or what head/ block whatever for a FORD in Super Stock will be acceptable---- Basically it must be OEM Factory stuff but they do give you a little leeway as long as their is no performance advantage over the factory astuff--- By that I mean it can be a more durable piece more heavy duty like 4 bolt main block vs. 2 bolt , but no performance advantage. Like more HORSEPOWER !!!!!!! Comp 387