Having just back fitted AC to a 6 pack motor for a friend....is your idle pulley lining up with the water pump and outer crank pulley? Angle of picture is deceiving. The reason I ask, the small cast 2 hole spacer also comes in different lengths depending on year. Additionally the 4 crank pulley come in slightly different size beside the asymmetric/ uniform hole pattern. 68ish? and down used a 5/8" PS belt, while 69ish? up used the 1/4" belt, which pushed the outer pulley out further. Hence the different spacer piece.