Ok. I usually know my way around my truck. I mean most people i know- know that i know a lot about cars and stuff. Hell, ive helped rebuild a 78 350, a 700r4 from a 90 suburban, installed lift kits...and numerous other projects.

So this makes me feel really stupid when i ask what an underdrive pulley is? Obviously its on the belt system hooked on the harmonic balancer right? What does it do?

 

ok nevermind i found out what they are....i dont like the sound of them...messing with the alternator, waterpump and crank...sounds like trouble if you ask me.

 

And I think the real gain in performance is minimal.

 

Thats what i would think. I'd rather have a piece of mind than screw with the pulleys.

 

FX4 Matt told me his 1/4 mile time went from 15.4 to 15.38 with the change in pulleys. Not enough for the expense. You don't know until you try but his experience would suggest that it may not be worth it.

 

I wouldn't mind an underdrive pully for my A/C compressor