OK, just wondering about the perrin pulley install. How are you supposed to tell when you have the belts tensioned right??? I watched the install video, and they just say something generic like "make sure you are happy with the belt tension"...well WTF does that mean? Thanks in advance.

Just tighten it till there is no slack in the belt and the belt does not slip. If the belt slips then tighten it more.

The only way to do it exactly is to a specification is to get a special tool like this: http://www.etoolcart.com/index.asp?PageAction=VIEWPROD&ProdID=1061

Also once the belt has almost no slack at all do not tighten it further, doing so will cause premature wear on the belt and/or components hooked up to the belt.

There should be about 1/4 of an inch slack in the belt when you push on it half way between the pullies. Other than that listen for squeeks, if you hear them, tighten the belt a little bit.