I know of a guy who says he's willing to part with his '78 F250 Supercab 4x4 with no engine and nice steel flatbed. It has sat for at least 5 years and I'm sure I can get it for cheap. It has no engine, a C6 trans, NP205 T-case, D44 front and D60 rear but most of all I'm pleased with the body being rust-free and only the underside has a little rust.
At home I already have a '78 Bronco for a weekend toy, my '96 F350 4x4 460CI(semi-daily driver), and my '78 F250 Snow Fighter with D60's front/rear. The reason I want this Supercab is to replace '96 F350 regular cab. The '96 runs fine but has a cramped interior. It's a pain in the butt trying to go places with the family in this truck so I'm looking for a Supercab and I'm going back to only driving '79 and older trucks.
Being that I put a ZF5 in my '96, the shifter is an issue when I tow or haul with it, I can only take part of the family along with me due to lack of seating. The '78 Supercab has a full bench seat front and rear for the family. I also have a bed lined up for this truck with a cap so we can all take it camping.
Anyway, the question I'm asking is, what engine/trans. should I go with?
I won't be using this truck for a diehard tow rig or anything but on occasion, maybe a handful of times per year I will be pulling a 12,000lb. load. I will mostly be hauling firewood and building material in the bed. I won't be going with tires any taller than maybe 35's. I would be off-road on my tractor trails getting wood quite often so I will need oversized mud tires but nothing too tall like I said.
I'm not sure what gear ratio the axles have but I might swap in my D60's from my Snow Fighter because they have 3.54's and with a granny-low manual transmission like the NP435, the RPM's shouldn't be too high on the highway with something like 33in. tires.
My Drivetrain Choices: *all options include an NP205 transfer case*
--I love the simplicity, reliability, and awesome low-end torque of a 300 inline 6 so that is my first choice. If I go with this engine it will be down to three transmissions: NP435, T18, or ZF5
The ZF would be nice on the highway but I prefer having all cast iron underneith my truck on the trail and the ZF would be the weak link.
--I am thinking about taking my 400(408) out of my Bronco and putting that in the Supercab since it will have all the power for hauling but it would suffer in the MPG department. It gets about 8-10mpg but has about 380hp. With that engine I wouldn't care what trans is used since it will have plenty of power and not require the help off the line when hauling that a manual transmission offers.
--My final choice is a 6.9 or 7.3 idi diesel. I don't want a powerstroke so that is not even an option. I don't want anything computerized or fuel injected going into this old classic. Simplicity and ease of maintenance is key. I have always wanted a 6.9/T19 combo in a 78/79 F250/350 all my life but have never got around to it. If I found one with a C6, would that be fine too? I know the C6 is stout since I've owned plenty, but does an old 6.9 really lag in power with a C6 compared to a T19?
I know this would be the best choice for hauling and fuel mileage but I'm still on the fence about all three options.
If I choose the 4.9 gas or 6.9/7.3 diesel, I will have to rebuild them before putting them in the Supercab, just to be safe. They are my favorite options but they will cost the most. If that's the route I go, how much would it cost for these engines to be rebuilt?
If I go with the 408 that I already have, I don't have to pay for an engine to begin with and I won't have to rebuild it since it only has 18K miles on it. I also have a C6 for this engine that I rebuilt with only 5K miles on it. This is the cheapest route initially but it's my least favorite option and the least fuel efficient option. Even though the 408 is rebuilt I still would trust a junkyard 300-I6 to outlast it, plus, the fuel mileage is a big concern.
I don't know guys, should I just use what I have already or make this Supercab what I've always wanted?
I'll try to upload a pic of the truck I'm talking about.

 

When I first got my Scab, I promised myself it would get D60's, a 460 and manual tranny. It is getting closer to being there. If I were to get another, I would really consider the I6 just as a DD/work here and there truck. I had an 89 with an I6 and I really got a lot of appreciation for that engine. 460 is nice, but gas is expensive. I rebuilt the top end of the 89 6 for a couple hundred bux (bought a rebuilt head) so those are cheap to fix anyday. For what you'd save on the other options, you could squeeze more power out of the 6 as well.

One day I will own a 2wd Crewcab and I will go the Diesel route with it to make it a dedicated trailer puller. I have no desire to mess with putting one in a Scab because as soon as I do I'll wish I had more room inside.

 

I am really leaning towards the inline 6 option for fuel mileage, ease of maintenance, cost of parts, ruggedness, and being a good all around engine. However, it would be just as nice to have a 6.9 under the hood and maybe later swap in one of my 78/79 D60 fronts.
Even though the 6.9 is a rugged diesel engine, the I6 is just as stout. It's a great design and gas is cheaper than diesel. The I6 is so tough it's almost built like a diesel. I know where to find plenty of all the engines I mentioned so it's not really a matter of what I can find, it's a matter of what do I choose?

 

I'm wrapping up a 78 F350 reg cab dually onto an 89 F350 dually chassis swap. If you go to the thread... The age old question... you'll see the info I gave him on this swap. the Zf5 trans with the hydraulic cylinder is a pain in the butt, but it's doable if you have access to a welder and have the patience to do a lot of measuring, cutting and drilling. Otherwise I would stick with a linkage set up. Theres a few other swap threads that I'm following and I'll look for them if you want

 

First, see how cheap you can get it for......Based upon my locale, its economy and whats for sale at what price, an F250 Supercab 4x4 without an engine thats sat for 5 years, i would only consider "cheap" to be $1000 or less, preferably less. Its got a D44 front, not a D60, so i wouldnt pay a premium price. If its sat for 5 or more years, have brakes frozen up, or lost all fluid in MC? If you can get it for cheap enough, why not just toss a 460 into it, in a heavy 3/4 ton 4x4, fuel mileage with a gas engine wont likely be good no matter what gas engine you choose.......I would suspect that in many areas, its easier to find a cheap used 460 than a 300, and the 6.9/7.3 NA engines are going to require a bunch of fuel system changes.

 

I already talked to the owners friend and he is willing to part with it for around 5 or $600 and seeing as how you just don't see these trucks in my neck of the woods, I'd be willing to pay double that, easily. I've only seen one other 73-79 Supercab in the last 15 years.
I'm not concerned about the brakes or fuel lines or any other minuscule issue since I already plan on starting from scratch in those areas. Either that or I will just swap one of my D60 fronts and D70 rears on it that I have laying around.
I appreciate the advice but the 460 is not on my list for a reason. I currently have a 460 in my truck and it's not what I want. The truck is not that heavy and even if it was a crew cab, the 300 has plenty enough power with a 4-speed and gets better fuel mileage than a 460. Besides that, I'm going for a dream truck build and the 460 is not on my list for my dream truck. I want a 78/79 Supercab with the engines I previously listed. I've had 70's, 80's and 90's trucks with 460's and don't care for single digit mileage. Not anymore at least. When I was single or back in my crazy years it was fine to waste money on gas to joy ride but now with kids and bills, I'm getting tired of having a 460. The 460 IS NOT on my list.
I've owned trucks with the 4.9 and only when they are not properly maintained or else, set up wrong do they ever get poor mileage.
Whether it's a 4.9, 6.9, or a 7.5(which it wont be), all of those options are fairly straightforward swaps. Also, where I live, there are more IDI diesels and 300's in the salvage yard than 460's. The only 460's around here all have automatics behind them whereas the 4.9's and IDI's can be found with manual trans.
The appeal of the 4.9's longevity, simple design, and low cost to maintain really have me wanting one but the diesel clatter and exhaust roar of the IDI while banging my own gears is just plain perma-grin inducing.
Can I get your votes between the two engines?

 

Yeah, I would most likely go with the NP435 or T18 behind the 300 instead of the ZF because I like having all iron/steel from engine down to the axles. The ZF swap is something I've done before and unless it's done on a year truck that had one offered as an option and already has the firewall hole for the master cylinder and pedals made to fit, it can be a pain in the butt.

 

Nobody wants to say which engine of the two they would choose?

 

On the farm we ran a lot of I 6's because they lasted forever and a day, supplied enough torque to run a PTO and 3 point hitch. They had good fuel economy and didn't overheat and they were easier to service. We didn't run air or race them, we used them as reliable work motors.

 

Yeah at $500 or $600 you cant go wrong, buy it! As far as engine goes, i just might decide based on whats around at the right price......the Diesel spec'd T19 tranny sure drives nice, having all forward gears synchro'd is handy. I suppose a question relates to how soon do you want it drivable, figuring that a 300 might go in on a weekend, connect a few fuel lines, some wires, one good battery.....could be good to go quickly.Probably use the existing radiator, front springs with the 300, while the 6.9 will require a lot more stuff out of a donor vehicle.

 

I'm coming here from the diesel world like my name would suggest. Had 2 cummins and one 6.9 turbo and a 7.3 na. Loved them all. But if your going for a "dream" truck. I'd do a cummins 4bt. All mechanical and have been known to get 25mpgs in a full size truck. On Craigslist in Phoenix there are 3 for sale for like 1k$ that's what I'd do. But a turbo idi with a 5 speed and a brownie box would be a cool combo. Just my 02.

 

Sorry buddy, it's my dream not yours.

 

And thats perhaps part of the problem here.....It IS your dream, do you really want to know what we might choose, and why? the 6.9 does have better torque than the 300, and diesel is a safer fuel than gasoline.......I also like the T19 better than the Np435

 

I would vote for the 6.9 simply for the "cool" factor. Since it seems like you are willing to do whatever it takes for any of the motors that you listed the 6.9 with the T19 would be pretty awesome. I'm only 22 years old so I am still easily excitable about truck stuff and the I6 just isn't as exciting to me. Although I am well aware of the durability and torque that comes with the I6 the diesel just sounds like a cooler option to me

 

Sure I'm going to be building MY dream truck but all three engines I've listed could just as well be part of that dream build. I'm just wondering which of those drivetrain options you guys would go with. I'm trying to weigh those options in order to decide what will work best for me. Hearing from people who have the exact drivetrains I'm considering is a help for me in making my decision.
The thing that annoys me is when people don't listen to what is being asked or just disregard it. I only listed those particular engines and transmissions because that is THE ONLY options I'm willing to go with and I've made that clear. Hearing guys waste their time suggesting things that are not on the list just aggravates me because I can't stand people who don't listen.
Anyway, does anyone have any more personal experience with the drivetrains I've listed that they're willing to share?