I have an HO roller block with no fuel pump eccentric on front of the cam for the mechanical fuel pump. I dug around at my dads house and found 4 eccentrics. 3 are one piece and 1 was the outer piece of a 2 piece eccentric. I know the one piece eccentrics were out of 390 motors. Anybody know if they are the same size as the 302 eccentrics?