i have an 1990 4x4 ford f150 that i love but the only down fall is the 302 i use this truck to tow mid sized trailers up and over the mountain passes of washington once or twice a year and it has been taking a toll on my little motor i recently came upon a new (crate) 390 for cheap and i could not pass it up i have the a 5 speed throttle body 302 now and i was wondering how hard would a swap to the 390 be and what i might encounter along the way as far as hangups.

 

I would think everything from the frame up, including all accessory (power steering, ac, etc.) will be different.
I had a 1968 390 in a F250 that I hopped up in 1980. It was a real fire breather!
Get to know your local wrecking yard...

 

The 390 won't bolt to your transmission. The motor mounts won't work. That's just the beginning. You would have to do a mountain of modifications. Any money you would save on the cheap engine would cost over and over in modifications. I'd look for a 351.

 

I also say look for a 351.

 

Here you go...

https://www.ford-trucks.com/forums/5...-150-pics.html

There would be very little difference between doing this on a 90 and an 85.

 

thanks for all the help, are yall saying the 351 would bolt right up thats why its easier because if thats the case i also have one of those but i need to build it up i just have the block.

 

The motor mounts and transmission will bolt right up. The exhaust manifolds and the front of the engine are about 2 inches wider. You may be able to cut the exhaust header Y pipe in the correct place and modify it to work. There will probably be a few minor issues with the accessories that bolt on the front of the engine. I don't know about the computer.

 

WHY ? The 351 W is the best simplest choice and with the right gear some free flowing exhaust and a few simple mods you will be pleased!My advice is to find a donor truck that will have all the parts especially since the 351 trucks have an oil cooler and usually the factory tranny cooler good luck and you wont regret it

 

the intakes are different thats is it. every thing else will work on a 351w from a 302.but dont waste your time on building a ford small block if you are going to pull or haul stuff with your truck. go a head and do the 390 swap better motor for that app than a sbf.i my self am doing a 390 swap in a 95 f150 cause of the same reason as you too little power out of a small block. and before anyone goes and gets there panties in a bunch i like sbf in cars not truck.

 

you can build a screaming small block and save yourself money and time rather than trying to put a 390 in that truck. a roller 351 with an appropriate cam, 4.11 gears, and some headers would be a suggestion. the motor itself is lighter, it'll push far more than enough torque, and itll pull decent mpg's. The truck I drive everyday has a mostly unmodified 351w in it, aside from a flowmaster muffler, and it'll pull anything I put behind it with ease. just my suggestion I guess.

 

it would be easier to swap in a 460 then doing a 390 swap in any truck manufactured after 1985.

most 390s are great motors but not ball busters either especially in stock form. a 460 would be a way better choice.

I am all for the 5.8 in this case but understand that gearing in your truck is going to play the largest role when towing anything.

 

I'll do a +1 for the 351 and a +.5 for the 460

You found out why the 302 isn't a very good truck motor. It was great in cars but never belonged in a truck.

The 351 would be a very easy swap and it has been documented several times on this site. It is a good truck motor especially with the few mods as mentioned and should serve you well for what you're doing.

I love the 390. I personally believe that it was one of, if not the best, all round motor ever made. Built for the purpose, it can do anything from low revving heavy towing to high PRM oval track duty. But in this case it would be more than it's worth to get it swapped in. The trans would have to be changed, motor mounts built from scratch, an entire front dress rounded up and a new exhaust fabbed (I would think manifolds could work but I doubt there's a header made for this apt). And after the whole thing is in you have to wonder if it would be emission legal in your area.

If you need more power that a 351 can give you then a 460 would be easier than a FE. You can get a lot of factory parts to make this work. There are also a couple of aftermarket companies that make parts to make this a bolt in. Plus those swap parts are relatively cheap and work.

On a side note, if you are pulling loads that require a big block then you may want to step up to a chassis to go with it. Getting a load up a grade is fairly easy but getting it down the other side safely is another story. You can get 460 powered 250/350s cheap these days.

 

thank you that just goes to show that there are people out there that know what a real motor is. yes the 351w can do better than a 302 but still open up your wallet with all the things that you need to make it run right. hear is a list of what the 351w needs ( better flowing heads, cam, intake, headers, mufflers, better rods, and pistons,) now the 390 ( nothing) as for the headers go find you a 60 through 73 ford truck that have headers out of a junk yard.and it will fit the frames are the same on any ford truck.just the motor mounts are different.

 

the 390 was never much of a powerhouse, the 351 is alot easier swap. i went from a 95 with a 302 to a 96 with a 351 and i pull 3 to 4 days a week and there is no comparison the 351 is an amazing engine. ive ran alot of 360s and 390s in trucks when i was younger but they were never a powerhouse. just my 2 cents. goodluck on whatever you decide

 

no, no. don't get me wrong here, the 390 is a good motor, i agree with you there. and if it was a less difficult swap to do, id be right with you in suggesting it. However, since the original motor is a 302, a 351w swap would be the simplest option. it doesn't necessarily need better heads, better rods, or pistons. If i had unlimited funds to stick into a 351w sure, but if the truck is just to tow, id put a bigger cam in it that's got a little more snort, and put in a more efficient intake, and a set of shorty headers and be done with it.