I think I bought the wrong underdrive pulley for my B18A1. This B18 came out of a 1990 Integra LS. I am thinking I bought a UDpulley for the newer B18 because my old alternator belt does not fit any more and is way too loose. I was wondering if I could just get a shorter diameter pulley and done? The New UnderDrivepulley I think is smaller in diameter than the stock. I lost the stock pulley.