I got my underdrive pulleys from Tbyrne. Came with belt and instructions. I had a friend do mine. He need a differant pulley puller to get it off, but with the right tool it came off fine. Make sure you get the pulley for the alterantor also. At lights volts are low but run on up to 14 on the gas.
1999 Silverado 1500 Ext. cab Red 2/4 hotchkis drop & swaybars, bilstein stocks, AR626 & 404 Nitto's, Yank converter, ASM headers, ASP underdrive pulley, Taylor wires , free mods VCN 2000, Nelson Performance tuning
2002 Red WS6 M6; Flow master K&N