good question!!

ok, my stepdad is a machinest and i was wonder if i could get the specs for all the pulley(not jus the underdrive) and lightened them up, would it do anything good? would it be worth trying to do? any1 have an pully's they would like to donate to bechopped up?

I'm not sure if I understand your question but I'll take a stab at it.

Aftermarket UDP's are made from aluminum and not steel like the factory ones. Machining it down would not be worth the trouble.

Maybe if he could make the other pulley wheels out of aluminum it might free some hp up, but its probably not worth it.

oh ok, thnx man.