I have an 83 CJ with the serp belt and run a york with the V-belt. I grabbed a V pully from a big car(dont ask I dont know) that was the same size as my idler pully. I had CANYON CITY 4X4(ask for Chippy) weld the two pullies together and make a bracket. Works great and doesnt vibrate.
Rob
83 CJ5 4.2 t176 300 4.56
Rob
83 CJ5 4.2 t176 300 4.56