I am no tranny guy, and I may have said this before, but when I was looking to rebuild my SM420, I got some info that might be of interest. A local large tranny rebuilding shop offered a rebuilt exchange, but insisted that you had to have the factory top plate with the shifter forks that matched your tranny. They explained that they were a individual factory setup and if you didn't have the mated top plate, they would not exchange it. Just repeating what I was told.
Steve O
