which carburetor!

[prostreetC-10]

KQQL IT
Actually, I know what you mean. You have an idle, trans and main circuit. If you land on it, you pretty much eliminate the trans circuit. That flat feel should be lean spot and flooring it will jump past it. Can be an incorrect HG rating of power valve. More than likely though a pump shot that is not quite set up right. Might not be enough. Sometimes guys will adjust the pump arm too far into the swing so they are running out of shot before the main circuit is fully taking over. Sometimes it's a carb winding up with the wrong pump cam because of an experimental previous owner.

When a guy wants to chase something like this down, the best thing to do is to get a few new gaskets and completely set the carb back up to factory Holley specs and go from there. Should be 78 jets, 31 shooters and pink pump cam on the #1 hole. JUST take the slack out of the pump arm. Don't do the feeler gauge bit.

C-10 KID
Seldom will an 850 have a better cruise range than a 950. 850s usually suck on the street because of the huge 1 9/16th venturies. Very temperamental and hard to get to not be lean jumpy. Usually just good for WOT but then again....cruising around town at 3,000 is pretty high.

Doesn't your 950 have removeable bleeds? Drilling them will ruin them. You need a precision drill set and drilling them will slow down the mix but also lean it out which might make your problem worse.