WTB small block carb ASAP

I was in the same boat recently, so I installed a "known good" new 2 barrel Carter carb on a 4-barrel adapter since I had run it a year before on the factory 2 barrel intake of my 273. I agree with pishta, even the tiniest 1-barrel would give the rpms you want in neutral.

I wasn't so lucky. The carb kept overflowing until I found I had dropped the float needle during my new plumbing. Then my re-wiring and not using the brown ign wire made no spark while cranking (didn't know the ignition switch does that), plus a few other "oops". I ended up running <2000 rpm a lot and too much cranking. Still my new cam seems to have survived fine, probably because I used a lot of assembly lube, have only 130 lb springs, and hydraulic leak-down lifters. I hope better luck with your engine startup.