Jon's post about the vacuum leakage is 100% correct. And Doc, not to be argumentative, but of the 5 Rochester B and BC models I used in the study, 2 of them had warped float bowls...warped enough to need straightening. So, I couldn't agree it is extremely rare. As for the 2 gasket answer, please see the attached image of one of the 5 (which had been "rebuilt" by somebody who used 2 gaskets). As the arrow shows one gasket was sucked out or popped out and created a nice new vacuum leak and fuel slosher. Also I'll show the 3 different sizes of seat fuel orifice I found in these. Which is correct? The data no longer exists or at least a comprehensive search on my part (involving one gentleman retired from GM) couldn't find it. The Carter engineers knew the size of that orifice made a difference. In the 3211s, they used a smaller one to remedy the flooding problem. And I found 3 completely different strength of springs on the power piston. Jon tells me there were several different ones used. Did the "rebuilder" get this right? That is to say did he keep all the parts separate when the thing was left soaking overnight? I'd bet money against it. As I proved, these can be straightened back to within .0015"~.002" and personally I'll bet that exceeds the state of condition when they were new, but unless this is going to be a trailer queen, your friend might want his Carter back...to most eyes and minds it is an improvement over the Rochester.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
