new belt?
 

I have a set of underdrive pulleys (crank, waterpump, and alt) on order and was wondering if I need to get a new belt or will the idler do the work for me?

depends on what size belt is on it (how much travel is left on the idler).....and .....how it's run....(whether anthing i deleted .....a/c thermactor ect)

It's completely stock at the moment, with a/c, stock belt, etc.

Are they MAC pulleys? I had these and I didn't need a new belt. If they are mac, I will warn you. Get ready for a new battery and a few alternators. Some people have had luck with the high output alternators. I didn't try one.

I was going to order the MAC pulleys on monday because of the holiday weekend, do you recommend a set that wouldn't have a problem charging my battery (FRPP, BBK, ASP)?

I recommend you check into a set of March Performance Power & Amp pulleys... this kit comes with an overdrive pulley for the alternator, and they advertise 10HP to the rear wheels. The billet aluminum ones are the nicest set of pulleys I've ever seen, but they are pricey compared to the steel (heavy) pulley kits. If you got the dough, get billet aluminum... http://forums.stangnet.com/images/smilies/thumb.gif

rule of thumb... less rotating mass = more power