ok this might sound like a stupid question , but. i want to take off my smog and ac. and i want to put an underdrive crank pulley on.

so what kind of belt am i gonna need , and can i get it at the local auto part store?

 

belt length, dunno, but here is how ya do it...

make a diagram of the left over accesories on paper and note the direction they turn.

Now, make a layout on that making sure that all the accesories turn in the same direction as before.

Noe get some string/fishing line ect, and lay it through thte system like you made your diagram. When you come to the tensioner, run the line about an inch from the bottom of the tensioner pully. This will give you a length that the tensioner can still keep tight.

Simply tie the two ends togeather, and go to the parts store and say here...

If it comes out that it is slightly too long, go back and get a 1" shorter belt.

EDIT:
get a 5 or 6 rib belt, not positive honestly, look at you stock one and count the ribs...