Which pulleys are you guys running on your 6-71's I seen you can run 3" or 2"? How much clearance do you have in front? I have double fans on my radiator I guess if it's to close I can get different ones that push from the front?
I run 85mm wide 14mm GT pitch. Old Top Alcohol setup (they are back to 8mm now). 3.4" wide belt, it is a monster. This required a wider idler pulley and some machine work. But I like it.