<VV> Carter AFB on 66 140 Monza Convert

[Sweet, Bill]

All,
 
Do any of you good guys out there in VairLand know what is the best
Jet/metering rod combo to use on the 550 CFM Carter AFB?
I have one on my 66 but, would like to get better mileage than my
present 20+.
The carb works well, performance is OK, but I think the mileage could be
better, and I detect a bit of black exhaust on occasion with an
up-to-temp engine.
 
Bill Sweet
 
66 Monza 140 Convert