I just found out the hard way that the '65-'66 eight inch rear has a real inherent weakness. The pinion carrier lacks any "meat" around the pinion support bearing and is prone to cracking even under moderate torque. In '67 an improved version of the carrier was developed by Ford. You can see the extra casting below the support bearing, and the increased ribbing on the case itself in the photo below.



It's a flaw to be aware of, Ford changed it fora reason.

I caught it before anything but the carrier was damaged, and I found a '67 carrier locally for seventy-five bucks so I'm not gonna kick the dog or anything. Still, a part of me wants to go back to Corvettes, I never had a Chevy rear schit the bed.

 

Interesting, thanks for the info.