rear end question

[cdg1984]

What all modifications need to be done to fit an f body 8.5 rear into a g body? Thanks!!

 

[Bonnewagon]

F body 8.5" as in 70' to 81' ? Forget it. The carrier lacks the "ears" for the upper control arms. If it did have them, then all you would need to do was cut off the leaf spring perches and then weld on the lower control arm brackets. Of course if you could fabricate some bolt or weld on brackets for the upper control arms, you would be a zillionaire overnight. FWIW the 67' F body rear has the "ears" since the rear was actually an A body rear pressed into service for the new-for-67' F line. Those A body rears are supposed to be pretty close to G body dimensions. But it's an 8.2" rear, not as strong.

 

[JBreu]

Scrap that idea and look for a "A" or another "G" body rear........... Won't happen, not today or tomorrow 🙁

 

[cdg1984]

what about the 80s f bodies. did they have any rears better than the 7.5

 

[jrm81bu]

It would also be quite a bit wider. But I suppose you could narrow it. As for the upper ears, if you are really set on trying it, I have seen(and thought about doing the same) bending a bar to run from the axle tube on one side over the center and to the axle tube on the other side. That would/could position the mounts for the ears too high, so I would also make this bar go slightly behind the center section so you could build your "ears" on the front of the bar. That would make it pretty close to stock position. I would also add some braces from the back of the bar down to the lower bolts for the rear cover, making them removable from the bar so you can still access the internals. That is if any of that made any sense to anyone but myself.

I may still do this myself and if I do, I will make a lil build thread anbout it.

 

[jrm81bu]

what about the 80s f bodies. did they have any rears better than the 7.5

Not really. Thet had the 9 bolt but I doubt its any stronger. and you would still have a problem with mounting it. The later rears did use the zexel torsion posi unit which you could put that in your existing rear along with the required 28 spline axles and you would have a small upgrade.

 

[Bonnewagon]

This is why the famed GN 8.5 rear goes for so much ca$$$$h. It IS an F body rear with the "ears" cast in and the LCA brackets welded on. They made so few that they pass for gold. Now if you could figure a way to add leaf springs to a G body, then the F body rear is the one to use. Interresting, right?