thanks mkiiisupra

i read that post from chambers too and it got me rethinking the underdrive pulley. i've decide that mod is not worth the risk. i appreciate the post though.

STAY AWAY from the underdrive pulley. If you are only using it as a race or drag car then go for it. But then you might as well remove the A/C, P/S as well. Our stock ones have a damper built in and it will destroy your engine with vibrations as Chambers stated. You can buy an underdrive pulley that has a damper built in but I believe it's around 900 bucks. I will let you know if I find it. You would not gain any significant power from it, maybe only up to 8hp anyways. They always promote more power than usual because they go with the max power than has even been made from them and in most cases was not on the car your buying it for. Go with a aluminum flywheel.... it takes about 40HP to drive the stock flywheel and with an aluminum one under 15HP. Also go with headers, significant gains can be made from racing headers. I made racing headers and exhaust system myself and have Huge gain! you can hear the difference and really feel it. Have yet to dyno it, but will post pics and the specs once I get the time