435/dana21 to 435/1345 upgrade?

[3gen4x4]

I have a 67 f100 4x4 with a 300 six, NP435, and a Dana 21 t-case. The 435 is old, sloppy, and grinds really bad going into 3rd gear. I can double clutch on the up shift, but down shifting to 3rd is a pain in the bum. I was going to order a rebuild kit for the 435 and just rebuild it myself, but the dana 21 is old and a single speed t-case. I have a 435/borg warner 1345 combo out of a 1986 f150 4x4 that is just sitting around. Is this upgrade possible? Will I run into any serious issues if I try to swap them out. I haven't looked at them side by side so mostly i am worried if the front drive is on the correct side on the 1345 for the 67 front end. Just for some extra info I have the drivelines out of the 86, plenty of tools and equipment at my disposal and a good garage.
Thanks

[averagef250]

The offset of the 1345 is wide enough that it and the frame rail both need to be in the same place. You can cut a pretty good size notch out of the lower lip of the frame and it will fit.

You can bolt a 205 up to that newer 435 if you wanted. It might make things a bit more bolt in.