1972 F100 4x4 trans swap
 

Hey guys, just picked up a 72 f100 4x4 351 4 speed and am looking to swap in a 390 C6 out a 70 f100 2 wheel drive. Will the transfer case in the 4x4 bolt up to the C6?

The FE (360, 390) C-6 won't bolt up to your 351 as the cases are different. You would need a small block case. The 2wd C-6 won't bolt up to a married transfer case which the original is a Dana 21 single speed case. You would need the longer 4wd tailshaft, and TC adapter. Are you sure you have a 351 whether a Windsor, M/400, or Cleveland as they never came with a 351. Are you swapping in the 390 also?

Ok, i haven't really had a good look at the engine yet, the guy i'm buying it from claims its a 352 industrial but when i did some research i found that engine wasnt available in 72. So i thought maybe it would be a 351, but it may very well be a 360, I'll have to have a good look. As far as the trans goes, i was just wondering if transfer cases can bolt up to 2wd trans like some chevys can but if they're a solid case i guess i can't. By the way, my 390 is a mercury. Do they have different trans case bolt patterns like the chev/pontiac turbo 350s did? thanks for the help

Check your VIN as a Y engine code means a 360 which it probably is unless it was changed. With a few exceptions, most FE blocks have 352 cast into them, so everybody says that they are a 352, except when it is a 390 on sale day, and a 352 or 360 when it is "in your hands" day. The only reliable way to know what it is is to measure the stroke. And AFAIK, Ford doesn't have any Chevy or BOP type tranny fitups, but I could be wrong.

Mercury engine of the same displacement (390) would be the same. If you do in cact have a 351, it could be am "M" engine, in which case it would have a common bell housing pattern with a 429/460. Or it could be a Windsor which shares a pattern with late 289.302 and 300-6.
At any rate, your transfer case isn't going to bolt up to any 2wd transmission without a complete tear dwon and some new parts.
I'd be looking for a combo from a F-150 so you could upgrade to a 205 transfer case with 2 speeds, as long as your changing drive trains.