swapping out ring and pinion 7 1/4

Dan, I agree. The only thing I know for sure is, I have been playing with 63-66 "A" bodies, since 1974. I have never seen a "shim" type 7 1/4. I have also never seen a cone type SG for the 7 1/4. Do you know if there is any number on the axle housing that could point to a year? I still have several 7 1/4 years, I could look at.