Depends on the overlap of the cam. The GT2-3 should cost you no boost (not enough to notice anyway)
My cam cost me 2psi. It has 52* of overlap. That's why I have a GT2-3 sitting in my garage.

 

If the picture actually attaches, if measured at the lines on the right I get 3.2". Measurement on the left is unknown. Does this help?

 

I guess my drawing in paint that took me half an hour to draw is not uploading. Too big. So forget that. After reading my last post, and noticing more people have posted, I see 1slowhoe has the best way to measure it. Now if I measured there and got 3.2" without using the "paper" technique, I am assuming I have a 3.2"

It is way to late to pop off belt and do that right now. Maybe on Monday though.

Thanks guys!! Now I wonder where my boost is. Will wait and see what my tuner says I had on his scanner when he did the tune. If guage is way off, new guage required. I want to get a Interceptor guage but am waiting on another post to see if it will read boost on 2 bar MAP. If guage is not off, WTF, it made good power on dyno and runs as strong now as it always has.

 

I believe all pulleys are stock. But I bought this truck used. Everything else looked completely stock so I hope it is. What is stock crank pulley OD??

 

7.5 inches

 

Dont know th OD of the crank pulley off the top of my head. Maybe somebody has one laying around to measure.

If I use a tape measure and measure from lip to lip on the pulley I get:
3 1/8" = 3.2"
3 5/8" = 3.4"

Good luck

 

Thanks everyone. Need to get some sleep now...zzzz

 

you are the one i was referencing to and i thought that you had a gt2-3 and that is what you lost boost with i just remembered your thread on your cam install and how you lost 2 psi boost with a cam