i installed the pulley as one of my first mods. i could tell very little performance difference, but the engine felt like it revved faster, and took less throttle to accelerate.

 

what do they cost?

 

I think its worth it. I have not done this mod yet, but plan on doing it soon... thats why I've been doing my homework.

Back in the day, "smoke_ur_5.0" gained 12rwhp and 7tq with the ASP UD pulley. Link That plus the shorty belt which "La Chochita" gained 10rwhp and 13tq for a total of 22rwhp and 20tq for ~$250 plus labor. I don't think thats too bad.

Like Ap said, he gained .2 w/ the UD pulley and v8 went from a 13.44@99.30 to a 13.26@100.02 after shortbelting... so thats about a .4 gain at the track w/ ud pulley and shorty belt together.

btw, all these trucks are 5.3s.

 

Whats the part number for the short belt? It just cuts out the alternator correct?

 

on my little 4.8L i could tell a big difference. first mod was CAI, then i ported the TB, and did tb bypass. next was the UD pulley, then elec fans. the elec fans seemed to help more then the UD pulley;. but with the 4.8L maybe its easier to see gians when you remove that extra weight.

 

6 rib, 60" long with stock pulley
6 rib, 55" long with u/d pulley
bypasses the p/s and alt.

 

ill be using a SLP 25% underdrive pulley on the 408. i need a pulley and the SLP one is SFI so kill two birds with one stone

 

we've put one on a buddy of mine's gto. it's a very nice piece

 

This is my take on adding a pulley -> link

 

yea thats why i went with it. shoudl be here this week. along with my proshifted t56