You need jet extensions and need to solve that pressure drop issue.
Too small a carb won't cause your problem. Neither will too tight of a converter.

The car is still surging down the track...by then the suspension has settled. I still say this is a fuel delivery issue.
You do need to do some suspension tuning, but that isn't the cause of your immediate problem. I fought the bouncing 60' w/ Cal-Tracs years ago too.

The A2000 should be plenty of pump as long as everything else is up to par. You could have a bad piece of fuel line...the AN braided line can deteriorate and come apart inside causing restrictions.