My '53 Chev 3/4 has run a little rough since my restoration was completed and I'm starting to wonder if I have the right carb. Here's the situation. The truck had a '55 235 in it when I bought it. The carb was a Carter YF-2101S which according to the manual is correct for 55-56. I replaced the '55 235 with a '61 235 out of a '61 Chev Biscayne. That engine didn't come with a carb and I went ahead and used the Carter YF-2101S. It starts and it runs, but is sluggish and I have to keep the throttle pulled out about half-way to keep it running. Driving it is not cool because it wants to stall constantly. In checking a few sources, I'm seeing that a '61 235 had a Rochester BC carb. Both the Rochester and the Carter are downdraft carbs. I also found 2 different carb model numbers and no indication as to which one would be appropriate for the Biscayne motor. A '61 Motors manual lists a model BC-7013003 and also a BC-7019000 for '61 vehicles without specifying which one would go with a Biscayne of that model year. Then a later Motors Truck manual lists a Rochester 'B' (not 'BC') for 60-62 with a model number of 7015011. I'm guessing that one of the two BC model carbs would be appropriate for a Biscayne CAR motor of that year, but that's as far as I can get. Does anyone have a parts manual or something that would give additional information as to which is appropriate? Would it matter which model I use for that year? And last, would this likely lead to the problem I described in the first place? Any help would be appreciated. Thanks.

1953 Chevy 3600 3/4-Ton