Thread: pully size? (not the sc pulley)

My sc belt has been looking a little worn here lately. A big groove has worn into the back of it so I started looking to see what its rubbing on. I track it down to the idler pulley just above the crank (2 o'clock or so) is gone. So I stop at the auto parts store to pick up a new one. They have 4 different ones... one grooved and one smooth. If I remeberright I need the smooth one but do I need the 3" or the 3 1/2"?

In the tech lounge, there's a sticky with a engine pulley list. Beleive it also has part numbers. Should get ya in the right direction.

Thanks for the help guys.... I didn't think to search the tech lounge