My truck (1955.1 GMC) is missing a bell housing behind the 248. I bought a T5 (86 model from a S-10). The owner of the S-10 gave me two bell housings. I think he was using the sell to clean his parts pile. Anyway, one is from a 70's model camper truck with a straight 6 and a 3 on the tree. Is that what I need here? How can I tell for sure?