95 Silverado 5.7 TBI bogs down at WOT won't rev past 3500RPM?

95 Silverado 4wd ext cab 5.7 TBI . Runs and drives great if you drive normally but if you punch it, it bogs and stumbles until you back off the throttle a bit then it quickly straightens out again. i put in new distributor, cap, rotor, plugs and wires about 10,000 miles ago. It was misfiring and that cured the missing. I set the timing to factory spec on the underhood label at that time. It now has 157K and uses very little oil, no smoke or anything. No service engine soon light either. Could it be a TPS issue. How about fuel pressure or a clogged cat? I don't think so but am wondering if anyone out there knows some common problems with these TBI motors that sound related to my symptoms. If you floor it though it will kick down and labor in ping gear and not rev past 3500 and seems to lack power. But when i back off a bit it will straighten out and pick up. You just can't get over 75% throttle. Idles fine too. I drove it from Tulsa to Minnesota just fine as well, any Ideas?