like i said he has been in the business for over 40 years...
Bob Jennings works with all types of carburetors, not just tuning for racing, but for streetability also.
the street avenger carbs arent just bad for racing..they're cheap in general.
Like i said i bought the 670 street avenger when i had no idea what a good carb was and ya i changed the jets and the vacuum secondary spring and ran 12.85s with it...so i mean you can get them to work alright, but in general you will have problems with it...i wouldnt recommend buying one...if you really want to buy one, i'll sell you mine for $100
this is one of those issues where its good to know what carburetor NOT to buy...the worst carburetor to buy is the Truck Avenger then the Street Avenger...these are words right out of the mouth of a really experienced mechanic, Bob Jennings