[FlatheadTed]

37 Fan is 15 ,1/2 .it runs in front of the stock coil were 35 is 15 .3/4 it runs above the stock coil You will need to play with the belts as Ramjet suggested .The Coil adapter will take 6 or 12 v.The fan mounting size is same on both ,3, 7/8 ! Ted