Ronnie, you could certainly swap the throttle bodies and see what happens.
To me it depends on whether the entire carburetor is the wrong one or whether only one part of it was mis-matched. In any case, it is worth a try. At this point you can't return it to Rock Auto nor to Autoline, so what is to lose? The frustrating thing is Rochester produced something like 140 different "B" models, so statistically the likelihood of parts getting mixed up is almost 100%.
Years ago...probably 40 years ago I got an eye-opening look at how one of the largest carburetor rebuilders in the Dallas area at that time operated. Why was I there? They had suffered a fire or two and the insurance company wanted to know if the problem of solvent storage had been fixed. Three things I remember: the speed and monotony at which the assemblers worked (think of something out of a Charles Dickens novel), the fact each person only worked on one model or type that particular shift and the fact all parts had been put in wire baskets by people working as dis-assemblers the day or shift before and soaked in concrete vats. One smaller basket had floats, one had jets, needles, screws, clips, small parts, another larger basket had air horns, float bowls and throttle bodies were in a different larger basket. The place was illuminated by about 3 or 4 fluorescent tubes and there were no windows. The disassemblers worked in more or less an open air area. There was a sign on the front which said "Now Hiring" and it looked as if it had never been removed. So here is how an assembler (we'll call him Charlie) would "rebuild" a carburetor: He'd grab an air horn from one basket, new needles and seats out of a box and float or floats from his another basket plus accelerator pump if that was the style of that model, shake the float to see if he heard anything sloshing around in there and then assemble and measure float levels. He'd set that aside, grab a float bowl, install jets and anything else that went into the bowl. Then he'd grab a gasket from a flat box, some screws and join float bowl and air horn and another gasket and attach the throttle body and connect linkage. Quality control? One guy was walking around drinking a Coke and chewing on a cigar making sure Charlie and the others weren't slacking, joking or talking to each other. Aside from the float/needle & seat I didn't see any other adjustment made at any time. The entire procedure took maybe 3 minutes. So I asked the gentleman I was with "how does he know he matched the original parts?" Answer: "There is no way he could do that and it doesn't matter anyhow. We keep like parts together and we operate on percentages here. We've learned we can mix/match and if there are no cracks or holes in it and all the shafts move, generally the carburetor will work ok as long as we get a new needle and seat and gaskets in there. And if it doesn't, the buyer will take it back to the store and we'll rebuild it again." He added as an afterthought "Mostly people just want it to look good." So there's a glimpse into one "professional rebuilder".
