Okay, maybe I could try that to see if it's the gauge. The good news is I do hit the 8psi with the 4.00 earlier than 7000, maybe even 6000, so that's good. I do have long tubes and full O/R exhaust, and from what I have read on here and other sources, that will have a little bit of a lowering effect on boost pressure (less restriction). It seems to feel like it hits a wall a little bit at 6700 and above, almost the same feeling as when I was N/A with the stock IM before changing to the Boss IM. Lund is asking for another log to investigate that a little more...