E4OD to C6 conversion?

My 91 F-150's E4OD has about had enough of the 9 inches of lift and 37s going over rocks ruts and through mud. With 210K miles its about to go. It recently quit shifting past 2nd gear but then started back a week or so later out of nowhere. I'm soon going to be using the truck off-road only and will have 1-ton axles and bigger than 37's hopefully. I dont believe the electronic trans will hold up to what I want to do, and Im not real certain about the BW transfer case either. i have a 79 parts truck(rear end) with a c6 and NP205 but it has a 400 motor, where mine is a 351W. I dont believe the trans will even bolt up. Even if it does or I find one that will, what will I have to do to make the EFI still work properly. Is there a way and is it worth the $ and the trouble? I like fuel injection because I know how to work on it. I'm clueless when it comes to a carburater and will not get rid of fuel injection, even if i have to keep the E4OD. I mainly need to know if that transmission has its own computer or module or if the same computer controls it and the motor. I dont know what i would do about the speed sensor in the transfer case, i know it has a lot to do with the computer(nothin works right when it dont). Maybe Im an idiot for trying to do this with a ford, but i never claimed to be smart. Any help at all will be GREATLY appreciated.

to be totally honest with you, i would scrap the 351 the 208, and the e40d and put the 400, c6 and 205 in your truck and learn about carburetion, or you could put fuel injection on it. you will get more torque out of the 400 than the 351. and no the c6 won't bolt up to your 351. if you plan on building an off road only rig, 210k miles is a lot on the engine and it probably won't handle the work load much longer. the 208 is aluminum and will probably break, either the housing or the chain. and i believe the computer controls the engine, tranny, or you can rebuild your e40d and hope it holds up. a c4 will fit your truck, but ain't sure how to bypass the computer.  hope this helps  

The 351W in my truck only has about 70K on it, it was replaced shortly after I got the truck so I definetely dont want to trash a good powerplant. I know that the right C6 will bolt up because a friend of mine has a truck with a Winsor and C6(just had the trans built, i went with him to the shop to get it looked at). As for putting the 400 in it, i've heard a lot about reliability problems with those and I have already decided if I put a different motor in it will probably be a 460, since I have one that just needs built if I want it, would just have to find a fuel injection for it. The E4OD in my truck has recently been acting much better(replaced throttle position sensor and added some Lucas) so Im not in as big of a hurry as I originally was, but still looking for a way to make the C6 idea work. I figure there has got to be a kit or trick someone knows to fool the computer. Ive found its hard to get anything by ford's ECM though...still on the drawing board

that's cool, i misinterpreted about your engine mileage, i also meant to tell you that the c6 wouldn't bolt up as it was, but you can change the bell housing, (if you can find one) and it will, sorry for not paying attention as i was typing. as far as the reliability on a 400 goes, that can happen with any engine on any day, i like the 460 idea, that's what i got and wouldn't trade it for anything, big block hp rules. i got a buddy i work with who knows how to fool the computer, as soon as he gets back in town, i'll ask him and get back to you. edelbrock makes a fuel injection for a 460. and i think holley does too. like i said, sorry about the mix up of words