You can probably make the 302/auto. fit,the problem I forsee is the oil sump is on the wrong end on most Ford smallblocks.You'll at least have to buy an oil pan pump and pick up tube for a four wheel drive,and THAT may not give you enough clearance to make it fit. You'll also probably end up re-shaping the floor to clear your transmission. If you already have the '60's engine bay vacant,it wouldn't hurt to try setting it in,and see how it fits.
In all honesty,if it was me doing this,I'd sell the 302/auto. and buy a smallblock Chevy and maybe find a Saginaw 3 speed/Overdrive for it,I'm not sure what automatics will fit the '60-'63 frame. (BTW-if you find a Saginaw 4 speed.I'm told it's possible to install the three speed's overdrive on it. If you go this route,it's ALWAYS best to use the factory mounts if possible,same goes for linkages and brackets.This truck was available with a smallblock so try to use as much of the original hardware as you can. You should be able to make it fit and look like it was born there.
Speed