SM420 upgrade

I'm going to look at an SM420 trans tomorrow morning to hopefully look at for an upgrade to my '67 CJ5. Is there anything I should look for? Years I don't want, with or without drivline brake assy.? The owner says it came out of a '64 chevy and it has the driveline brake assy. attached to the back of it. Is this a good candidate?
Thanks!

 

Yeah. You want the 2WD version, although I've never found anything but that in the junkyard. Drop the drum brake and leave it there. Make sure the output shaft is 10-spline 'cause that's what most of the adapters are built to mate to. I got mine out of an early '60s Chevy pickup. Can't remember the year but it was something like a '61. Also, make sure it has the shifter. They're hard to find.

 

Also pull the top cove and look inside. look for rust or signs of water. the big gear is bound to have some wear in the edge of the teeth but the rest should look good. look at the face of the teeth if all of the gears for pitting or signs of wear. check the cane shifter for wear or repairs. look at the front input for a seal. the early SM420s did not have a seal but can be upgraded. Novak has a good page on them. see link below.

http://www.novak-adapt.com/knowledge/sm420.htm

 

I thought the sm420 and the sm465 had the same shifter. I see them a lot on ebay. I do hear they are a PITA to change