I'm replacing my rod bearings in my engine after running low on oil. It looks like I have two different size bearings though, three sets are stamped A and the other three are B. When I look up the part on Mopar I only get one part number, does anyone know what the letters mean, or do you k ow a way for me to k ow what size bearings I have? There are more numbers on the bearings but there the same for each set, I can add those when I get home if that helps.

 

I have read that the factory has +/- sized bearings to match production tolerances in the rods and crank journals.

The bigger issue is that if the bearings need to be replaced due to low oil pressure, the crank journals and large end of the rod need to be re-sized. Then thicker bearings are used to match the re-sizing.