I just pulled the cover on a Dana 44 front in an '80 Chevy. Stamped on the ring gear is the date 1977 and 50-11, which divides out to 4.545. I went to rotate the pinion, and clunk. The pinion gear barely even touches the ring gear. Nothing's chewed up or broken, they just dont mesh. I'm thinking someone stuck a 4.55 Dana 44 ring gear on a 4.10 carrier. Does that sound like a feasible explanation?