Cummins 4BT & Diesel Conversions Forums banner

Mid 70's Ford trucks...best candidate for a swap?

17K views 29 replies 8 participants last post by  twiisted71 
#1 ·
Hi all,

This is my first post here on the forums. I first want to say that you guys have an awesome wealth of information here, and from the threads I have been reading it seems like a good group of people too. Hats off to you guys. :grinpimp:

I'm a construction worker who had his eyes peeled for a powerstroke until I stumbled upon a 78' F150 with a 4bt in it for sale. It was outside of my price range, but it got me doing my research and I soon discovered this site. I've been ghosting for about a week now, trying to figure as much out on my own as possible, however I've come up short when trying to dig for mid 70's fords...

For some reason the mid 70's Ford (6th gen bodystyle) just calls to me when I think about trucks. It'll be a year or more before I have the money to drop on a 4bt or 6bt to swap, but in the meantime I need a truck to drive and could get started on the interior renovation and any body work. However, as far as which of the three major ones would lend themselves most to a swap, I'm at a loss. I've been looking over F100's, F150's (1975+), and F250's. 4WD will be necessary for sure. I know that engine weight becomes an issue with regards to front suspension, and from what I gather it seems as though lifting the suspension a bit helps things clear on the bottom end (if I read correctly, a 4bt is 37" tall from oil pan to valve covers...that seems big)...this would leave me to believe that a F250 highboy might have a slightly easier time than a F100, no? :confused: Are there specific options in the mid 70's Fords that might be desirable in a swap? (brake options, transmission options, etc)

I know you guys probably get noob posts all the time. Rest assured I'm a pretty avid self-teacher...but some expert advice at this key point in the project would be much appreciated. Thanks in advance!

-Simba
 
See less See more
#2 · (Edited)
a F250 highboy might have a slightly easier time than a F100, no?
-Simba
Welcome Simba,

The trucks have the same bodies and same engine compartments. Any could swallow a 4BT without blinking. Choice of trucks can depend on desired usage. If you want a mean rock bashing monster get a late '70s F350 with the Dana 60 front axle with open knuckles and disk brakes and high pinion.

Otherwise get a '75-up F150 or 250 so you get high pinion Dana 44 with open knuckles and disk brakes. If you can find an F250 it'd net you bigger brakes and a larger rear axle but the F150's 9" and Dana 44 with standard brakes are plenty fine for a 4BT.

If going for a 6BT look for the F350s I described above so you can get that big Dana 60 front axle with kingpins instead of balljoints and monster axle shafts

You could get the same 4 speed and NP205 TC in all of them.
Be careful of the F100 as they could have a TC that doesn't offer a low range! But I have seen them with factory hydro assist steering!!!
 
#5 ·
Thanks for the info! I don't need a rock crawler, but I do need something with power. There's alot of hills in western north carolina, and doing roof construction (my trade) means throwing 2000+ lbs in the bed from time to time. I've heard the 6bt's are a bit easier to find these days as well compared to the 4bt's. Good to know that the engine compartment is the same size across the board.

I'll keep an eye out for a F350, but the only ones I've found are 2WD duallys, and that's more truck than I want for a daily driver. Would a 250 with Dana 44's be sufficient for a 6bt, or am I going to become really familiar with replacing ball joints after taking it through the local dump repeatedly?
 
#7 ·
Would a 250 with Dana 44's be sufficient for a 6bt, or am I going to become really familiar with replacing ball joints after taking it through the local dump repeatedly?
I wouldn't suggest the 44 under a 6BT. The weight and Tq of the engine could break the axle shaft joints pretty easily in 4wd. You could always buy whatever clean truck you find and just pony up the dough and put a 60 under it. There are even parts that will allow you to mount the 60 to the existing radius arm/coil spring suspension!

I lived in A-ville for several years and my in-laws are in Brevard!
 
#9 ·
I'd stay with the f250 for the reason of leaf spring front axle verses coil on the f150.

Also I believe that he f250 mostly had divorced transfer cases which will make the swap easier.

On the newer f series trucks 80-90's ive read that the 4bt drops in place easier when there was a 300 6 cylinder in the truck..idk if this holds true on the 70's
 
#10 ·
I believe you're right about the divorced transfer case in the 4wd 250's...every highboy I've looked at has that. A 250 seems like the best open-end option for me :) you guys have been very helpful so far

Anyone know if the camper special variants (140" wheelbase) complicate a future swap at all?

The ease of the 150 300 swap for the mid 80's / early 90's is very tempting, especially since that straight 6 is a 300K motor in itself, allowing plenty of time to make the conversion. There's just something about the mid 70's Ford that I love though...is there a specific reason that the straight 6 300 is more desirable? More recessed firewall? Engine mount location? This is simply my curiosity asking.
 
#11 ·
When the 4bt was retrofitted into the E350 step vans the engine that came out was a 300 six so a mid 80's ford with a 300 and manual transmission is almost a direct swap,if the 4bt came from a Ford van and it still has the transmission and motor mounts attached. I did this on a 73 and it worked out OK. I changed horses later and am putting the engine in a 53 Studebaker (SOON I HOPE). I believe it would be pretty much the same scenario for a mid to late 70's if you swap out the motor mount setup from a mid 80's truck.
 
#12 · (Edited)
Guess i should clarify my other post, what i meant to say is that in the 80-90's body style the 300-6 can be pulled out and a 4bt can almost be a drop in replacement... very little to do to the engine mounts ect. This may very well be the case on the 70's body style with a 300-6 also. The preference for the 300 has to do with the frame mounts,,, but IDK anymore... use the search feature and look at some of those build....

As far as the camper special question, if the truck had a truck bed there should only be two wheelbases SWB and LWB... camper specials usually had extra leaf springs, shocks, maybe a larger alt and brakes... wheelbase would be the same as a stardard LWB truck

I think this would be a nice truck,,, one sold on ebay about 3-4 months ago... red late 70's 3/4 with white steel wheels,,, looked real mean.
 
#13 ·
If you look at a true camper special they have a long bed with an altered rear wheelbase.

There were also different cab configurations in short and long bed non CS trucks.

If you stick with the '78-'79 f250s you'll get the high pinion d60 (which is what you want) you'll get a married TC. Don't over think the swap. You can put anything together you want to you just have to scrounge the parts. If you aren't afraid to take on this swap then don't worry about the details. You can easily work them out. Most anything you buy that old is going to require a full rebuild before I'd trust it in a brand new built vehicle anyway so parts cost is going to be close to a wash from stuff you get on an older '70s truck that you don't want to use vs a newer '70s truck with more desirable parts that also need rebuilding. Spend a little more on the newer truck out of the gate and you won't have to scrounge as many of the good parts.
 
#14 ·
Simba, the 78-79 body is still the same as 73-77. They just change the front grille area and added square head lights. The trucks from that time period are tough. I bought a 73 new and kept it over 30 years. If you're thinking F100/F150 I'd say go 4bt. For the F250/F350 the 6bt. Over all the 6bt will cost less because it is more readily available. If I remember correctly, the Dana 60 front axle was an option in the F250's but it isn't all that easy to find one. A good axle swap into the older trucks would be a 87-91 F350. Should be just about a bolt in. May require a new front drive shaft. Change to one of the Ford ZF transmission to get the OD. The fun thing is trying to find a good truck of that vintage. They aren't as plentiful as they once were.
 
#26 ·
The 78-79 dana 60 front are not the same as the later ones, they have a completely different center section with different spring mount spacing and the differential is located in a complete different location. It is not a bolt in swap and without widening the spring mount centers on the 70s vintage fords will not work for on road applications
 
#15 ·
Wow!!! You guys have gone above and beyond with the advise here. More than I could have hoped for. I'll be sure to post a picture when I finally find this horse. Char is right, these things are getting harder to find. But it's good to know that I have some flexibility with parts if I do some heavy scrounging. It'll have to be based off of what is available locally of course. Thank you to all who have posted.

Twisted is right on the CS wheelbase. If you look on ebay right now, virtually every 70's 250 for sale right now is claiming it's a camper special. Only a couple actually are. Alot of these sellers like to throw the "highboy" tag on there to catch eyes as well. There's a F350 painted harley davidson colors that is a good example of a true camper with clear pictures, incase anyone is curious. I would post the link, but I need a post count of 10, lol:D The title of the sale is 1975 FORD F350 SUPER CAMPER SPECIAL HARLEY DAVIDSON "TRIBUTE EDITION" RANGER XLT...should come right up in a search.
 
#18 ·
I don't know why there was a negative comment about coil springs earlier but I'm actually getting rid of my leafs and going with coils for the better ride. I'm putting in a Ford hybrid 8 lug Dana 44 front axle/coils and radius arm suspension in my Jeep and could have used the leaf springs from the F250 I sourced one of the axles from and it would have bolted in! I've owned and driven both since the late '70s and for a true work truck I'd say go ahead and go with leaves. If its going to be a DD, I'll take coils over leafs in the front every time.

Again about the Dana 60s- be careful about what you are buying. Early ones had low pinion (not a terrible thing in itself), closed knuckles, and drum brakes. They are more suitable for boat anchors as there are MUCH better choices to be had.

You need to decide exactly what you REALLY want this truck for, and then start making smart decisions about what parts will meet these needs. Don't get suckered into the "everything needs a 60 with 4.56 gears and 44" tires" mentality, esp if you just want a nice DD capable of muddy roads, going to the camp, snow driving---BUT not rock racing, baja jumping, tough truck competition stadium racing!!! Smaller components that will meet your needs amply will weigh less, cost less, and likely be easier to find and once built and under the truck you'll never know the difference othre than peppier performance and better MPGs from hauling several hundred less pounds of iron around.
 
#19 ·
That's sound advice there, thank you. I'm basing most of my needs off of the trucks I've driven/used over the years at various companies. We tried several size variants. Little import 4 cylinders got trashed quick, then we drove them into the ground. 150's / 1500's held up pretty well, but definitely showed anove average wear down the road. Our 350's / 3500 did every job with ease and then some, even with after market steel flatbeds loaded with 8000lbs of trash (that's an extreme, but not exagerated, example). I won't be hauling that kind of weight myself, since I'm now self-employed and taking on smaller jobs. I think a 250 would be everything I need plus some. I think a 150 with some beefed suspension would get me by just fine as well. I'm keeping an eye out for both.

Saw a 1975 250 on my local craigslist today for $850. Unfortunitely it was 2WD and extended cab, which is a longer wheelbase than I'd want to deal with...longbed is a necessity, and a standard cab keeps it short enough to not be a PITA to drive (in my humble opinion). Thanks again for all the great feedback, you guys rock :)
 
#20 ·
Depending on when you start yours we are getting ready to stuff a 6bt in a 78 crew cab that will probably help you along on yours. We are going to try and make it look factory along with original a/c pump and pedals.


Sent from AutoGuide.com App
 
#27 ·
Simba, that is one thing you have to take into account when swapping axles. Ford did play around with frame widths in the 70's. You mentioned a Super Camper Special which as far as I know was never offered in 4wd. It was designed for a slide in camper and the spare tire was mounted in the side of the bed. Extremely HD. You rarely ever see one of those. Don't think they sold those by the zillions.
 
#28 ·
You're right about the no 4wd in the campers...I figured that out just yesterday on the phone with a guy who had one for sale. I may not be a mechanic, but I do know enough to measure before I just buy an axel. If I don't go with a 250, it's a non-issue anyway. Thanks for the heads up. If I end up with a 250, I'll be careful to source exactly what I need.

The more I think it over, the F150/4BT swap off of the 300 straight six sounds like a nice and relatively easy swap for a first project. Of course, it all still depends on what kind of truck I can find locally. Thanks to all of you guys, I now know what I'll be getting myself into depending on which truck I find. You guys all rock! :)
 
#29 ·
You're on the right track. Don't make it more complicated than it has to be. I always thought it would be interesting to take a F350 Super Camper Special and make it 4wd. It literally has the same frame as a F350 wrecker chasis with 140" wheel base. Would definitely be different, but I read they only built a very limited number of those. Hope to read about your swap soon.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top