I have/had the same pull through . From reading it appears as not unusual . As it only happens at high rpm/throttle/load just jet as needed be secondaries for best afr .
Tex
New best ET 10.259@129.65 . New best MPH 130.94 Finally fitted a solid cam, stepped it up a bit more 3690lbs through the mufflers New World block 3780lbs 10.278@130.80 . Wowser 10.253@130.24 footbraking from 1500rpm Power by Tex's Automotive
