The numbers 8.5 and 8.6 in this case refer to axles. The only major difference between the two is the width of the carrier bearings, which itself connects to a device known as a differential case, which not only protects the axle from the bearing, but also drives a number of gears in the mechanisms.
No, different dimensions.
Yes
65
8.5 3.73 Positrac
Just did mine w 85/140 coastal from autozone
80 or 85 W 90 gear oil.
Yes
Not without a LOT of modification. You need to get a rear end out of a '68-'72 GM A body for a direct bolt in. Anything else will require modification to properly fit.
Remove the you joint and driveshaft. Remove the rear end seal plate. Remove the seal and bearing. Reverse the process to install the new seal.
how do you remove rear window 85 feiro
85
14" on te front and 17" on the rear