I would be very skeptical unless they can give the the rod and jet specs for the carb. Most of these places are just rebuilding these carbs with mix matched parts. If they used the right parts they should be able to tell you the detailed specs. Here is a thread about this topic: http://www.v8buick.com/showthread.php?t=206168 I would get a hold of Ken: http://www.v8buick.com/forumdisplay.php?f=172
I may have a line on a good running '72 350 carb. Send me a pm if interested. And if you are not interested in trying to rebuild your own - I would consider sending your current unit off to Ken for evaluation. A medium flat rate postal box is under $11 to ship.
Rebuilt QJET carb from "National Carburetors" has #72 jets, K48 rods and "W" secondary rods. Allegedly all bushings and plugs are new,idle tubes are pulled during rebuild, pump cup is new and alcohol resistant but the other parts if OK would be refurbished or replaced new if not.
