The last time I swapped a motor in one of these I left the transmission in place.

I remember being in a hurry and wanting to swap the motor from one to the other, and vice versa, in a single weekend. It worked. I drove both away Sunday night.

1955 1st GMC Suburban | 1954 GMC 250 trailer puller project | 1954 GMC 250 Hydra-Matic | 1954 Chevy 3100 . 1947 Chevy COE | and more...
It's true. I really don't do anything but browse the Internet looking for trouble...