86 F-150 Engine Swap

Im in the process of swapping a 351M from a '79 f-150 into an '86. The '86 currently has a fuel injected 302, automatic trans (im not sure what trans it is, im assuming its stock) and 4wd. What i really need to know is what modifications am i gonna need to make to fit the 351 in. Will i need to swap the tranny and transfer case? Is there anything else major im gonna need to do? Sorry if these seem like dumb questions, but this is my first real big project. Any help you guys can give would be great.

you will need to use a different tranny and motor mounts. you need 351m exhaust manifolds. if you could use a 351w you would be better off.

you will need to use a different tranny and motor mounts. you need 351m exhaust manifolds. if you could use a 351w you would be better off.

manifolds wont be a problem, I'm runnin stacks through the hood, so I'm getting special headers (its gonna be a mud truck). I still have the tranny and transfer case from the other truck, but I was told it would bolt right up, like you can with GM small blocks. I assume i'd have to change the trannsmission mounts too?

If you still have the trans/transfer case from the 351M/ 79, youll need to use it. You may be able to swap bell housings if they are removeable, some trans were one piece units, not sure which you have. But the 351M will not bolt to the 302 bellhousing, different bolt pattern. A 351W however will bolt up, use the same motor mounts, and you can use the same exhaust. Its about 3" wider than the 302 at the deck, but its pretty much a bolt in swap.

If you still have the trans/transfer case from the 351M/ 79, youll need to use it. You may be able to swap bell housings if they are removeable, some trans were one piece units, not sure which you have. But the 351M will not bolt to the 302 bellhousing, different bolt pattern. A 351W however will bolt up, use the same motor mounts, and you can use the same exhaust. Its about 3" wider than the 302 at the deck, but its pretty much a bolt in swap.

Thanks for all the help so far guys.

Im building on a budget, so buying a different motor isnt really an option for me. The M is leftover from a '79 that i bought a couple years ago that had more wrong with it than I bargained for. How much work is changing the mounts gonna take?

Ive put 351M/400`s in 2wd trucks of that era, and the only problem i had was oil pan clearence on a couple. But on the 4wd you should have plenty. The frame pads for the motor mounts, are different from 79-86 on 2wd`s, but im not sure on the 4wd. If anything, you may have to drill a couple more holes in the pads, but i dont think youll have to change em. A little looking and measuring will tell you if the trans/transfer case mounts will work. Worst case you may have to fabricate some mounts, and lengthen/shorten/modify the driveshaft`s. If you know some one with a torch and welder, none of this is a problem. This is one reason we suggested the 351W, but if you gotta use the big block, its doable, but i dont think itll be a bolt in swap. Welcome to the world of motor swapping.

As long as my friends barn is empty, none of that stuff should be a big problem, he's got all the tools i'd need. The truck only cost me 150 bucks anyways, and I'll get that much worth of fun thrashing on the stock engine before i get around to the swap, so this is a good truck for me to start on.