anybody put underdrive pulleys on? notice any difference in power or any adverse effects?

I have the crank pulley, not really worth the $60 it cost me. If you can find one cheap, maybe pick it up, but i didnt really notice any difference. If youre running any sort of a sound system, dont do the crank and alternator, you may run into charging problems.

Crank and Alt pulleys here. Didn't notice a big difference if any at all. My problem now is my AMP gauge dips below 13v when sitting idle, all lights get dim. I've put in a new battery and a new alternator and it still does that. I do however still have my ground wire and another wire hooked to my radio when I had my system in the car. Doubt that's causing the problem tho.

I've got the crank and alt pulley and have a small amp. Never had a problem.

thanks. i'll take that as a not worth it.