Quote: well you would have thought all the ford engineers they would have came up with a way to fix there housing instead of buying complete rears from dana
Where is the logic in that?........Why didn't Chrysler design another rear instead of buying DANAs?.......For the same reason Ford didn't. Why engineer and tool up to make, what you can easily BUY. Why would ANY auto maker design a heavy duty "truck specific" rear, when you can already buy one of the best made, the DANA. The 9" came into play around the mid 50s, but they were designing a pass car and light truck rear, not a heavy duty truck rear, because they could get that from DANA. Same as Chevy, International, Studebaker, Chrysler and others.
Chrysler DID update the 8.75 from the small pinion rear that it was, to the larger unit for its hi-po cars, but obviously they didn't feel it stout enough for big block and HEMI cars, so they sourced DANA to build a pass car model. Ford on the other hand, felt their 9" WAS strong enough for their hi-po cars with a few upgrades, so they came out with the 31 spline, locker, nodular case, with better pinion support model, which WAS an extremely stout factory rear.
All 8.75s are not created the same and neither are 9" rears. While run of the mill 9s were weak, the hi-po model that came under super cars and some trucks and vans, was NOT. Same with 8.75s. The small pinion A-body type 8.75 is weak as water, but the larger pinion models are MUCH stronger, but still not nearly as strong as the BEST 9" rear. You have to compare apples to apples.
So, is the 9" as good and heavy as a DANA for a heavy duty truck app..........NO, because it was not designed to be that.
