Jim - I have lots of experience with the 2-G series Rochesters, and have probably rebuilt between 1500 and 2000 factory (and aftermarket) tripowers. However, we (as did the factory) reccommend using tripowers only on "torquer" engines, not "screamer" engines. "Screamer" engines work much better with dual quads due to the eddy currents created at the "join" at higher RPM's.
Rochester made literally hundreds of different 2-G carburetors. These vary in internal venturi size, fuel jet size, air jet size, etc.; so impossible to give a reccommendation on jets.
Often, an off idle hesitation is caused by using a vacuum guage to adjust the idle mixture, and adjusting for maximum vacuum (creats a "puddling" condition).
Cruise surge may be due to too lean jets; it may also be due to a camshaft mismatch to the vacuum requirements of the primary carburetor; and the usual cause of a cruise surge is because of some of the M/M aftermarket progressive linkage, which creates a minor vacuum leak at either the front or rear carb.
Finally, in the "food for thought" category: generally, if a PERFECTLY tuned tripower on a Chevy 350 is capable of a 13 second quarter-mile, then then same engine/vehicle with a proper 4-barrel would turn 12.50's; and with proper dual quads would turn 12.20's. This is why we don't like to play with tripower on a SBC.
If you really want to discuss this, feel free to call during normal office hours (see bio).
Jon.
