Double plumper carb or stay with Vac sec carb?

Double pumper,leave the air gap,try a 1" open spacer.(my.02). If becoming a track time car of any sort, start a log journal. Every pass,every change,record the results in that log journal. That will remind you of what works,and not doing it twice. Log rpm shift changes/launches,timing/carburetor, & combination changes.That way,you don't do the same thing twice. Fwiw,Rick's 9.5 converter idea,food for thought. Good luck.