I recently acquired a 1949 Studebaker that someone had installed a GMC rear and transmission, I am trying to figure out what kind of transmission it is, it does not have an identification plate on it and there is a couple casting numbers 591665, 591701, 591568 I tried looking then up and didn't have much luck, its a 10 spline and it feels like there is space for 4-5 gears but I can only get it to engage 2 gears.
The splines look like it fits to my 270 GMC

http://i1191.photobucket.com/albums/z476/akguy34/1949%20Studebacker/100_1502_zps0321f5d9.jpg

http://i1191.photobucket.com/albums/z476/akguy34/1949%20Studebacker/100_1501_zps84ec7ee3.jpg

http://i1191.photobucket.com/albums/z476/akguy34/1949%20Studebacker/100_1499_zpsffe9f86c.jpg

http://i1191.photobucket.com/albums/z476/akguy34/1949%20Studebacker/100_1496_zps30630b70.jpg

http://i1191.photobucket.com/albums/z476/akguy34/1949%20Studebacker/100_1495_zpse7f13dcc.jpg

http://i1191.photobucket.com/albums/z476/akguy34/1949%20Studebacker/100_1494_zps3eb5bcad.jpg

any help would be greatly appreciated.