I just bought a march underdrive pulley kit..now wen i got to put that on do i need a shorter belt ur that should be fine? (94z28)

 

An underdrive pulley will be smaller in diameter, so you will need a shorter belt. The exact length will depend on the dimensions of the pulley. March may be able to tell you the correct length, or you could try and measure it when you get the pulley on.

 

do u think if i just go to like advanced auto parts n ask for a smaller pulley they mite have it

 

You already have a smaller pulley.... you need a smaller belt. But there is no way a parts guy at an auto parts supply store can guess what length you need. You have to find out from March, find out from someone here who has the EXACT same March pulley (they make more than one), or measure it yourself. Put your old belt on, move the idler pulley so the pointer is within the required position marks, and estimate how much shorter it needs to be. Wrapping a string around a serpentine setup is a bit difficult.

The alternative would be to get the next smaller size belt, and try it, making sure you don't get it dirty, so it can be returned.

 

ok thanks iam gunna go over to the store now n get the next size smaller