Air conditioned olds v8 has a three groove water pump pulley. Sorry I don't know if it would help you or not. A friend has an olds, I could get measurements if needed. I am pretty sure it is less than 6 inches in diameter. Jay 6155
Ok I just got off the phone and got the measurements for the Olds three groove water pump pulley. These are approximate. If the pulley was on a table it would be about 3 3/4 inches tall. The three grooves are about 2 inches thick for all three grooves. The pulley is about 5 1/2 inches wide where the belt grooves are. I hope this helps. Jay6155