DUCKY:
Just curious of what size jets some of you are running. I have a Holley HP950 (80496-1) on a 8:1 468 chev with a little cam and headers. It came with 78's all the way around. I am up to 84's in the primaries and 90's in the secondaries and my friggin plugs are still white, and I have what sounds like a lean miss at WOT (which is only 4600rpm). I have a 6-valve mechanical pump at 6psi at WOT so delivery isn't an issue.
Oh yeah, I run at 500 ft alt. Sounds to me that you're running out of gas!, I just had a similar situation!!.If you're carb is the right size for the motor, you shouldn't need to go more than one or two sizes from factory jetting!..Are you running adequate size fuel lines?, you using a regulator or bypass?..I'm running a Victor454R and a 1050 on a 468. I have #12 line from the tank to one of George Streagle's high pressure mechanical pumps, #8 from the pump to the carb and a 8lbs bypass after the carb. Couldn't figure out at first why I couldn't pull more than 6000 even after dropping down in gears, raised the floats, up the jets, still 6000, plugs lean, WTF!, come to find out, the bypass was stuck open, popped a bowl, it was almost dry, wonder I didn't cook something!!.....Just my experience, something to look for!!...