The Stovebolt Site Forums The Shop Area Engine Shop I have an SM420 Question

My objective is to remove the torque tube style drive shaft and rearend and install a '69 camaro 10 bolt posi with highway friendly gears (2.73)'s. Wanting to stick with a truck style 4 speed (SM420, I thought I needed to get an open drive shaft style transmission .ie. '55-'67 SM420 transmission. I did purchase what I believe to be a '55 SM420.

OK, here's the deal... Upon scraping decades of dirt and New Mexico grime from my "54 1/2T with original SM420 4 speed transmission. It appears to me that I could just swap out the "transmission rear bearing retainer" with the one on the '55 and not have to swap transmissions.

Can someone shed some light on what may be my $250 and countless hours of cleaning 1955 "transmission rear bearing retainer"? Of course it is attached to what appears to be an excellent working transmission.

Thanks

I know someone who has done the rear retainer swap so while I can't tell you the details, I believe it can be done.

While you have it apart anyway I'd try to ascertain while transmission is in better condition and go with that one.

You ought to put new bearings and gaskets and replace anything else that needs it in the '55 tranny before you pull your rear end swap, then you'd have a known fresh tranny to go with it and won't have to wonder.