'51 Ton & 1/2 Eng Removal Q

[Mo Hardy]

Hi everyone,newbie here. I have a '51 1&1/2 ton Chev. I got a while back from the owner for work I did. He told me it had a bent valve, I got some new valves on ebay pretty cheep so I was gonna fix it. During tear down I found it had a bent push rod so I went back to ebay and got some of those. Got it running, lo and behold I found the water jacket cracked but it had been JB'd. But it was leaking. Funny thing was the guy I got it from is an automotive instructor for a major org.,I guess he just doesn't know as much about engines as he is accredited for. Good thing is the truck had been updated to the 235 high pressure eng. I finally found a good replacement and am ready to swap in the 'new' eng.
What I need to know is, can I support the tranny and pull the block&bell hsg only. I know lining up the tranny shaft on install can be a pain but pulling the tranny/pto with the engine looks like it would be a lot harder to do. I have the dual control pto so I would have to drop the 10 foot drive system for the dump cylinder also and it looks home made but usable. Yeah this was a Kansas wheat truck so I guess a farmer did the set up, but it does have potential.
If any of you have done it this way and give some do's and don'ts I would appreciate that and thanx in advance. Mo