The carb that my GMC 248 engine has is a Rochester. I want to install a Zenith (which is the correct one, but don't know which model). Checking at Jim Carter catalog, it only appears two Part No, for engines 1940-1947 and from 1948 to 1956 (the years might be wrong, I'm shooting from the hip). Checking the block casting number, the engine is a '55 248 engine, and according to the shop manual the carbs for 228, 248 and 270, although the same model (228), the Zenith part No is different, for instance the correct Zenith part number for that engine is the 11441-A. Checking venturi measurements, jet sizes, they vary from part No, to part No., even though, the model is the same (228). I called Jim Carter, and the girl told me that, as the catalog said, the carb would be the same within the years given. I'm new in the stovebolt world, so I might be taking the shop manual info to serious and the girl might be right (I didn't spoke with tech support, just the sales person). Is she correct or do I need to find the actual part number in order for the engine to work at its best efficency? I've come to realize this carb is not easily found. Is there anothe carb that can be used that will work OK? The Rochester in mine has been tuned and the engine seems to be working fine. I've found only Carter and Holley carbs around here. Does de 28 modern model of Zenith work, choosing the correct venturi (apparently they sell this model with different confgurations to work with different engines. Any idea where to find the appropriate carb?
Thanks you guys for any help.
Last edited by Chinito Quan; 08/21/2010 4:48 AM.
