MudderFinger helped me out with the 3.750" pulley install, so now I'm thinking I'll be heading to the dyno this weekend to see the new numbers and check the tune. I was surprised at how much boost .250" added, we both saw the guage push up to about 11.5lbs, about a 3lb jump from the 4.000." I'll be calling DTP today to see if they have room for me on Saturday morning. 583rwhp was my last pull with the 4.000" so I'm curious if I will be able to break into the 600s. I'll post the time if I can get an appointment if anybody would like to come out and see Little O go.