I need some help identifying this trannie that I recently bought. I bought it under the assumption that it was an SM420. I took it apart and noticed that ALL the gears were straight cut and there is no synchro! :confused: Here are a few pictures:

http://www.pirate4x4.com/forum/attachment.php?s=&postid=461967

http://home.off-road.com/~md11fr8dog/Graphics/SM420GearSet.jpg

http://www.pirate4x4.com/forum/attachment.php?s=&postid=459978

http://www.pirate4x4.com/forum/attachment.php?s=&postid=459464

Its by diganosed as a 1940-47 GM truck trannie, part #185 by someone else. The seller still insists that its an SM420, stating he got it out of a '50 GM 1 1/2 ton truck. Any advice? Anyone ever seen an SM420 with ALL straight cut gears and no synchro?

Thanks

Sean
Steamboat Springs, CO