I don't think the diablo chip gets rid of the stock rev limiter. Hmm, I don't think I've ever changed the fuel filter

Think that might have something to do with it? Would my fuel pressure increase after I changed it as a sign that maybe it was restricting pressure?
I think he said he couldn't add fuel past the 5000 RPM mark; I think he said the fuel system just wasn't keeping up to what he set it for. And my 255 in-tank is probably at least 3 years old; the T-Rex is only a year and a half old. The car has been a daily driver, and every so often get up and on it. I've only been to the track twice with the blower, once with street tires, the other with slicks.
What do you think???