Local Craigslist score - BBP 7-1/4"

I put one out out of a ‘75 valiant with 114,000 miles on the clock into my first ‘71 Duster \6 904 car to replace the original 7-1/4 that was roaring. It went through a lot of abuse spinning in snow and on wet roads and never whimpered or gave any trouble. I put it out to pasture after going 8-1/4 with 3.21s and unfortunately let time and weather have its way with it. My present 7-1/4s pinion bearings are making the vibration of impending doom like the driveshaft is running in an orbital rotation...