1000 rpm loss after carb & ign. repair

273 Commando engine - Holley 600 double pumper - HiPo cam, Edelbrock RPM intake - dual exhaust - port n polished heads
Last year I rebuilt the front end of my carb in order to cure the engine stumbling/hesitation at WOT between 2000-3000 rpms. (relaced gaskets, pwoer valve, float & needle....Anyway I use to shift her @ 6500rpms with this issue an after I cured the hesitation I now can only shift @ 5500rpm but she pulls hard @ WOT all the way through the power band. I also went from a Mopar Hi-Po distributor to a stock distributor because of a misdiagnosis of a fuel delivery issue. Did I lose the 1000rpms from 6500rpms because I corrected the 1000rpm hesitation @ 2000rpm & 3000rpm? Or did the stock distributor cause the 1000rpm loss from 6500rpm to 5500rpm?

Thx

ZooKypr