Lonnie - use a tailpipe sniffer. If the A/F ratio is less the 14, the power valve is probably open.
Wally - (strictly opinion, but you did ask). I don't like ANY of the Rochester single barrel carbs; whether you are talking B series, M series (monojet) or R series. On the other hand, with the exception of the AA and BB series, the Rochester 2 barrel carbs are in the top 5. Ditto for both the Rochester 4 jet and the Rochester Q-Jet.
I guess my top tier of single barrel carbs would be:
(1) Carter WA series
(2) Stromberg B series and Zenith 228 series
(3) Carter W series and Zenith 28 series
(4) Carter Y series (only this low because of the ethanol/diaphragm issue
(5) Holley 847 series
There are other good single barrel carbs that don't make the above list because of the cost of repair parts. These would include, but not in any order: Stromberg A, E, and W series; Zenith 20 and 23 series.
Series that I don't really care for would be, again not ranked: Carter AS, BBR, BBS, and RBS series, all Holleys except the 847 series, all Rochesters, Stromberg D series, and Zenith E and IN series. And I probably forgot something!
Remember - all of this is my opinion, others will differ.
Please understand I am not saying the single barrel Rochester carbs cannot be made to function (for awhile); I just don't like redoing something every so often because the manufacturor failed to spend a few extra cents to prevent the issue.
Just as something to shoot for: the dual 4-barrel Carters on my 1968 non-GM 390 truck haven't been touched in roughly 10 years (other than to change metering rods for E-10). At 70 MPH, the truck will get 22 MPG on gasoline, 19 MPG on E-10. The carbs are set up so that both run simultaneously.
And Ed - here is a picture of the "ridge" used to help seal the gaskets. Sanding and removing this ridge will guarantee issues:
http://www.thecarburetorshop.com/Rochestersealingridge.jpgJon.
