I have recently pulled a 1964 Hipo 289 small block out of a boat. It has the Cobr pan, Cobra intake, Cobra valve covers. The block casting number is c3oe-f and the heads are c3oe. On the back side of the engine below the left head is a stamped number 5478 and there is also a number stamped in the block on the front left head mating surface. Could any body tell me if there is any significance to those numbers? Thanks