I swapped tail housings for 2 reasons, where the shifter mounts was damaged like it was dropped on this area and my car has a cable driven speedo and I found a place that modifies the housing so it can run the speedo.

I have an aftermarket housing I bought new and when I put the reverse idler gear on it sits too high for the bracket to mount. If I remove one of the spacers that goes on ither side of the cage bearing it’ll go together. Has anyone had this issue?

 

In stock T-56 parts, there are 2 versions of extension housing. "Early" and "late" for lack of better words. I think it's like 95-back and 96-up butt don't take my word for it. Not sure if that applies to aftermarket ones, or if not, which stock version they match if any, or any such.

 

It is the 96-97 F units that were machined to remove the need for the washers. Nothing wrong with a 97 extension housing on a 95 box or the opposite. You just need to run the washers if needed.

 

A little update, I measured both of the tail housings where the hardened spacer goes and there is a 0.111 different between the two and that’s almost exactly what the spacer measures.

Now I get to take it to a machine shop and get this corrected.