I was browsing the LMC catalog and came across this page for engine swap kits.
Truck Parts and Truck Accessories

It lists kits for 57-64 and doesn't note between fitting 2 or 4 wheel drive. Were the 2x and 4x trucks similar enough in that era that these kits would work on both? I'm also wondering if my 65 F100 4x with the older leaf spring front suspension is much different than the 57-64 trucks mentioned. Assuming these kits do work on 4x trucks that is.

 

1961/64 F100/250 2WD & F350 and 1961/64 F100/250 4WD are similar.

1965 F100/250 4WD; 1965/66 F350; 1966 F250 4WD are similar to 1959/64 4WD, but some of the parts are not the same.

1965/66: Upper (upper) pic // 1964 (same as 1961/63): Lower pic (front only):

 

Anything can be made to work, those from LMC look a little light duty.

What engine do you want to swap? Hard to go wrong with an FE...

 

Just looking at options. Wouldn’t mind an OD five speed behind my 352 but don’t think there is anything available for that.

 

You thought wrong -
but I happen to know a guy
who could set you straight
if you're willing to wait
'cause he's seen many beers go bye
now he's gone

 

Where there is a will there is a way... I hadn’t heard of any bolt in options that work with the bellhousing mounts to frame I have.