[blue sky]

5 bolt bell housings only the have the narrow pattern. The wide trans mounting pattern came with the development of the J block (6 bolt). The 5 bolt block can only take the 157 tooth flywheel and the max pressure plate size is 10 1/2" (Ford long style, not sure on aftermarkets). To use the 11" pressure plate, one needs the 164 tooth flywheel.