re. Rochesters. I'm batting 2 for 4 in getting a good one.
All 4 that I have experience with are older manual choke models.
1 is the smaller 216 version and the other 3 are the larger 235 versions.
The one I rebuilt on my 49 216 runs flawlessly. I've got approx. 13K miles on it since rebuild and so far so good. No problems with it.
The 3 I tried for my 54 235 have differing problems. One hesitates in the acceleration circuit and I can't get it right, another has vacuum leaks around the throttle shaft and the other has warped body halves and leaks. I was able to make 1 good one but I need 2....
Rebuild kits aren't expensive and always worth a try, buying so called rebuilt carbs can be like buying a pig in a poke, you won't know till you buy it.... And they ain't cheap....
Good luck
Dave