Someone ran a light and t-boned my 87 XJ centered on the B pillar. Now it's bent in the middle and not much good.  It has a great running 4.0L and the p.o.s. peugeot and 231.  I would like to put the engine into my 54 willys truck.  It currently has a rusted, frozen up mid 60's ford 6 (200?) hanging in the frame and the original 3 spd. trans and T18 in the bed.

I would prefer to use an automatic for the easier swap but am open to a 5 spd. Either way I would like an overdrive so I can retain the orignal rearends if possible. I would consider swapping out the front diff to a left hand pot if there is something that will match up width wise. Disc brakes and open knuckles would be a good thing. I intend to put in a later model saginaw box.

Anybody have any thoughts or suggestions? 

If you want an auto, start with an auto donor, might as well go for an HO too.  Not real famililar with Ford but, maybe a 300 would be an easier swap. just because you have some parts laying around doesn't mean you should use them. if the original xfer case was an 18, then your rear end is off center, probably easier to keep the original and use an adapter to the tranny.