I pulled apart a 390 ford big block today and it has .030 over aftermarket pistons in it. The numbers on top of the piston are 4 0778 with 030 under that. Can anyone tell me who the manufacturer may be?
Im pretty sure the number on the top is the bore size. They should have something stamped on the inside of the piston. Is it a dome or? More details and possibly a pic would help.
