My truck won't climb RPM and pretty much falls on its face after a certain point. Seems to be around the 5000 RPM area with some boost. I already regapped my plugs down to .022". It is a 383 5.3 with 317 heads. 212/212 .560/.560 112 cam. gt5002 turbo. 5 inch exhaust. It almost feels/sounds like fuel cut, but the tune says otherwise. Fuel pressure was steady also. If you look at the frames between 2:20.21 to 2:20.28, it is pretty noticeable of WOT and watching the RPM ramp up pretty decent and then kind of plateau, all while be WOT.
Eric