'89 6 cylinder into a '65, will it work?

[65 P-30]

Hello again,

I've located an '89 1 ton with a 6 cylinder 4Sp, and I'd like to install the engine, and maybe the trans into a '65 step van that now has a 292 4Sp.
Will this be an easy swap, or are there major changes that will need to be over come?

On another note...
I'm new here, so I'd like to take a moment and provide a little of my history.
As far as the interchangeability of these drive line parts goes, I really should know all of this, and it's a little embarrassing to admit that I no longer do. I was a top notch wrench turner at one time, and knew just what fit in what, but there has been just too many years that have gone by since I've been messing around changing engines from this to that, and to be honest, I haven't a clue what will fit into what any more.
I guess that's what I get for walking away from what was my favorite pastime to concentrate on what the wife said I needed just before I gave up working on cars, and that was "a real job". To this day I do not understand just how someone that's working their butt off is supposed to take that comment.
I can still hear what she said, " You're not making any real money! You're just playing around with those cars! Just like you did with those stupid model cars when you were a kid! Quit screwing around and...wait for it...."get a real job"! ". OUCH! That stung. lol
So...with my limited attention span, I had to give up "playing" with cars, along with a few other interest that were deemed "to much fun".lol Gotta love her though. She kept me on the straight and narrow.
So, fast forward 35 years and here I am, CLUELESS!
The time has come to return to one of the things that I once was very good at, making something outta nothing.
If it was a GM made in the 60's, or early 70's I'm golden. The 80's get kinda iffy, but I'm trying to bone up on the changes.

End of my brief history, thanks for taking the time to read it, and thank you for any information on changing these engines out.