Speedometer Gear/Transmission Removal Questions

[NoDOHC]

I just finished the 4.30:1/Miata Torsen rear end swap. I made it all the way to the end before buggering something up. I didn't realize the GXL and GTUs speedometer driver gears were different diameters (GTUs is larger) and I smashed the speedometer driven gear in the transmission by forcing the install of the GTUs gear. The car drives just fine, but I no longer have a working speedometer.

I've done some searching/reading and it looks like the driver gear housing (the part that bolts to the transmission) is slightly different between the GXL and GTUs. It looks likw they are offset just enough to account for the difference in diameter as it appears all 2nd Gen RX-7's use the same driven gear in the transmission. When I received my GTUs driver gear I received just that, the gear, and therefore reused my GXL housing. I guess the others who've performed this swap changed over the driver gear and housing from the GTUs as I haven't read of this ever happening to anyone. Does this seem right?

So now I am in search of a GTUs driver gear housing and a new driven gear, but I have been unable to locate any part numbers whatsoever. The FSM lists them as "speedometer driver gear" and speedometer driven gear, there is no mention of the housing separately. Does anyone know these part numbers?

To replace the driven gear, it looks like, at the very least, the transmission extension housing, needs to be removed. I assume this means the entire transmission needs to come out, or is there a way to keep it bolted in while just removing the extension housing? If I do have to remove the entire transmission is there anything I should be aware of before I try?

Sorry for the long posts - I like to try to include as much information of my issues as possible.

[infernosg]

I just finished the 4.30:1/Miata Torsen rear end swap. I made it all the way to the end before buggering something up. I didn't realize the GXL and GTUs speedometer driver gears were different diameters (GTUs is larger) and I smashed the speedometer driven gear in the transmission by forcing the install of the GTUs gear. The car drives just fine, but I no longer have a working speedometer.

I've done some searching/reading and it looks like the driver gear housing (the part that bolts to the transmission) is slightly different between the GXL and GTUs. It looks likw they are offset just enough to account for the difference in diameter as it appears all 2nd Gen RX-7's use the same driven gear in the transmission. When I received my GTUs driver gear I received just that, the gear, and therefore reused my GXL housing. I guess the others who've performed this swap changed over the driver gear and housing from the GTUs as I haven't read of this ever happening to anyone. Does this seem right?

So now I am in search of a GTUs driver gear housing and a new driven gear, but I have been unable to locate any part numbers whatsoever. The FSM lists them as "speedometer driver gear" and speedometer driven gear, there is no mention of the housing separately. Does anyone know these part numbers?

To replace the driven gear, it looks like, at the very least, the transmission extension housing, needs to be removed. I assume this means the entire transmission needs to come out, or is there a way to keep it bolted in while just removing the extension housing? If I do have to remove the entire transmission is there anything I should be aware of before I try?

Sorry for the long posts - I like to try to include as much information of my issues as possible.