Where do you guys get your belts? I'm running a 6" crank, 2.75" on the SC. Currently have a belt from NAPA (41" HD green truck belt IIRC) and I think its slipping. The auto-tensioner looks maxed out and I can push/pull the belt about 3/4". Can't find any charts, and i'm thinking about putting on my 2.5" pulley soon. I want a good belt that will last. How many miles do they typically go before needing replacement? Any help appreciated, thanks!

 

You can go to gates.com and look up there catalog in pdf (sites down right now though), try looking at actual page# 659 (shows up as pg 757/789 on my droid). I just went thru this today on my car. I had originally ordered the 080400HD from Napa but it was too short when I tried to put it on this morning. I just ordered a Gates K080408 from amazon, my old belt measured 41.38" long. Unfortunately I couldn't find this in HD.

All of the belts on gates site are listed as Outside Circumference:
8 rib belts are 1-3/32"w (28mm)
080400 = 40.75OC (1034mm)
080408 = 41.38OC (1051mm)

Pretty sure I have the stock pulleys on my car as I only make 6#. You should be able to take your belt off, mark a line on it, and roll it on top of a tape measure or use a piece of string around it to check the length. Then just take that measurement and figure out what you need.

Might as well throw a new tensioner on there too:
Ford# F4TZ-6B209-A FORD 1994 F250 F350 E350 7.3L BELT TENSIONER ASSY
I bought mine off ebay awhile ago for $25 new


Hope this helps

 

I bought the same tensioner on ebay

I bought Gatorback Poly-v #4080415 and #4080407 from amazon.com. Got both shipped to my door for $24!! The napa belt on the car now was freakin $40. Going to install this weekend and see what happens, which belt works with 2.75 pulley. Then put on the 2.5" pulley and see if i have a belt that works.