I did an engine swap years ago in a 1963 Chevy Suburban. Took out a 292 I-6 and put in a mildly built 283 with headers and nice exhaust system.
It took a different front motor mount tower on the passengers side. I sourced the OEM fiberglass fan shroud for the shorter V-8. Everything else bolted right up.
I stopped by a friends auto repair shop while visiting my home town after the swap and told Rudy what I had done. He said "you ruined a nice truck", and I said take a look, and opened the hood.
He said wow Chris, can I take this up to my HS auto class to show the kids how such a thing should be done?
It went from a vehicle that would pull over a building with the 3.73 gears out back and a 4 speed truck tranny, that was NOT a freeway cruiser, to a truck that easily cruised at freeway speeds.
I was towing my friends E racing run about circle race boat at the time. Trips all over the NW were much more pleasant with the V-8 under the hood. I guy that build our boat motors built the 283 for me.