I recently had a big headache installing my AC delete pulley GM part number 10115875 on my 94 Z28. i'm making this thread to help anyone else having the problem, i searched without too much help.

My stock compressor pulley was 90mm diameter (about 4 inches). The supplied pulley with the bracket was 76mm (about 3 inches). from what i found, there is two different compressor pulley sizes, i dont know what years this covers.

I also have a crank underdrive pulley so my belt size is dayco part number 5060595 (6 rib 59.5"). The next smaller size available in a dayco belt (available at advance auto) is a 5060578 (57.8") and it is too short. you need a belt about 1 inch shorter for the smaller pulley if you're in this situation. i'm not sure what the stock belt size is for the stock crank pulley but i hope this helps save someone else from buying multiple belts and pulleys to try to get this to work.

 

I went through about 4 Goodyear Gator belts before I actually found the right one. What I did was i got a tape messure and I routed it around the pullys how the the belt would route. and took the messurment, remeber to get it alittle bigger cus of the belt tensioner. I think the last 3 digits of the goodyear gator belts are the size: IE 265 = 26.5"