Acme # 4612 --- 40.00 X 61.00 VR5B 2.50 .045Cup, .95 DAR, 7.5” hub length
Acme # 4613 --- 40.00 X 61.00 VL5B 2.50 .045Cup, .95 DAR, 7.5” hub length
It also depends upon the step ratio of the trans. There will be a metal plate attached to the trans with that ratio. Mine is 1:4.35
Also the above...