Greetings, looking for some advice on the Muncie M20 I have installed in my 65 frame off restoration project.

First, a problem, I was removing the speedometer driver gear tochange the gear ratio to match the rear end and the plastic gear slipped out of the housing and stayed in the transmission. When I reached up to grab it I touched it and it slipped into the rear extension housing. Now I can't reach it with several probes and I am looking at pulling the tranny apart to get it out.

My question to anyone with experience with these transmissions, Is it possible to back off the rear extension housing a few inches so I can get at this gear and remove it while the tranny is still mounted. When I look at the diagrams and reading the instruction for transmission service in the 1965PontiacTempest Chassis Shop Manual removing the rear extension housing while the transmission is still mounted seems to be possible. Any suggestion? Is this really dumb.

Obviously I would like to do this with as little effort as possible

Second is a general question, on my muncie the speedometer driver gear mounts on the passenger side of the car as opposed to the driver side as shown in the tempest manual. Obviously I purchased tranny for another model, probably a chevy {I really should check those numbers}. Is it possible to just replace the rear extension housing if I can find a proper Pontiac GTO housing?

Thanks for any reply. I will check back here or you can send an email to me at vossf@***.net