On an upper pulley, the same belt should work fine. You can use Lightning change out pulleys to do the same thing, but much easier to accomplish than an upper. I'm using interchangeable lower pulleys made by Metco Motorsports. A +2 will get you around 8.5 lbs., a +4 will get you around 10 psi of boost.

 

12-15 weeks!!... I wish mine would only be taking that long I've been waiting to get my tunner back from Mike for 8 months now... only reason I had to send it in was that Roush had to retune my computer so i had to send the new Roush tune to Mike... will say there is a night and day difference between the tunes, but it sucks not even being able to drive the truck fun because I have the larger pully on the crank and i'm just to lazy to change it out cause I keep telling myself that the tunner should be back soon...

hopefully I can get back to runnin my truck how I want to