[Richard Grant]

7lbs. is a lot of pressure for a quadrajet. I am surprised that you don't have other
problems. Try 5 or 6 and if it doesn't affect the et you will be better off in the long run. It might even help with your problem.
I don't know who does your carbs but some carbs will stumble coming off the trans brake. Try a carb from different builder, someone who has a track record of building quadrajets using a transbrake.
Also are you on a chip when you leave, some quadrajets don't leave well off a chip.