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Brand new to the site so I'm not completely sure what I'm doing on here. I have a 1979 f600 4x4 with a 370 4v. I'm pulling a 40' semi trailer with it and it pulls ok but doesn't like 5th gear at all. I'm toying with the idea of a 7.8 diesel and a roadranger but I like the 370. I just wish it had more power. Any advice would be helpful My ol 6 hundy My trailer
Not sure what you are doing. But, IMO, if this is a commercial operation, get a different, upgraded diesel tractor. I wouldn't fiddle with the f600. A 4x4 f600 is almost a cult item.
If it's just for personal use, remember you'll have to change gears or settle for a 40mph top speed.
There's always a 429 upgrade. It's an upgrade but not a miracle.
Upgrading to a 429 would be my first choice, they have a good bit more power than a 370, but it's still going to struggle with that trailer.
2nd choice would be a different truck, converting that one to diesel would involve a lot of work and cost.
Does that F-600 have a air brake system in order to operate the trailer brakes, if not my 2nd choice would move up to number 1
It has air over hydraulic. It is for commercial and personal use. I wanted to use the f600 because it is a 4x4 and any truck that has 4x4 that can pull it would cost way more than converting to a diesel. I was thinking about a 7.8l ford diesel from an f800. I also don't want to mess up the air conditioning in that truck. I have also toyed with a 534 v8
If you find a running F800 with the 7.8 hard to get parts for oil burner, you could probably fix it up to pull the trailer easier than swapping to the F600.
Air over hydraulic? The truck brakes are air over hydraulic or the trailer or both?
534? The 429 is a better choice. The 534 is nearly impossible to get parts for, and the 429 would probably run right with it.
The f600 has air over. The trailer is full airbrake. The thing is I need the 4x4 for what I'm doing with it and I don't know if I can find an f800 7.8 4x4. The parts issue is why I wasn't set on the 534. I don't know all that much about the 7.8 but from what I understand it made 2-300 hp an 400 tq. They are reliable but no powerhouse. I'm not sure about what I want to do because it would be cheaper to engine swap the f600 than to find a 4x4 or 6x6 that isn't an old military truck that is beyond destroyed.
My tach doesn't work but that truck doesn't go over 60. It has a Clark 5spd which to my knowledge was put behind the 7.8. the axles are Rockwell 5 tons and can handle it. They are 6.17 gears with a Rockwell 223 t case 2 spd
Let's back up a bit.... "What is your mission?".... Are you running a daily route and delivering a product in all sorts of Wyoming bad weather? You keep leaning towards the 4 wheel drive. Commercial trucks run 365 days a year and none have front wheel drive. They chain up in bad weather / snow / ice.
That is an old, heavy trailer. How much does your cargo weigh ? Total weight of trailer and cargo ?
How much money do you have to devote to more horse power / faster rig?
Having done a engine swap going from a V8 to in line 6 diesel I can tell you a few things that will need changed. 1st your transmission will not work behind a diesel, diesels use a common SAE style bell housing that your transmission won't bolt to, plus it's a lighter model Clark trans that won't hold up to the torque a diesel makes.
A in line 6 diesel is several inches longer than your 370 so you have to cut the fire wall and find or make a dog house to cover the back of the engine, this will move the transmission back as well plus a diesel trans is bigger and longer than your gas trans, these changes requires the transfer case to be moved and new drive shafts made, you'll need a larger radiator and these very little room between the grill and core support to mount a intercooler.
429 would be the simplest and will be a noticeable power increase but your still going to be under powered for pulling that trailer.
Not my favorite engine but Ford did use the Cat 3208 V8 diesel in that body style, it fills up the engine compartment and is a PIA to work on in the truck, but you don't need a intercooler, it's shorter and you may only have to bend the fire wall in some places, you'll still need a SAE style trans. With that combo you may get by with shortening the mid shaft between the trans and transfer case but I'm just guessing at that.
As has been asked is there a reason for needing a 4x4 truck to move the trailer
I want a 4x4 because when I go out to ranches out here in Wyoming (specifically sybille canyon area), that area gets to be almost impassable in the winter and a 2wd won't stand a chance (I speak from experience as I have gotten hopelessly stuck even with tire chains). I drive an 18 wheeler for my main job and this is my side/off hours work so I know just how much I can do with a chained up 2wd.
The trailer weighs 12500# empty I think. Cargo no more than 30000# in the box. Combined load on truck will not exceed 45000# total GCW less than 55000#
Cool truck! I toyed with the idea of retrofitting a 7.8 into our ‘74 f600. In the end it was way more practical to swap the cab of the ‘74 onto a ‘90 f800 frame and that’s what we did. The firewall has to be cut to make room for a engine that long. The tranny, axles driveshafts all need to be changed for the previously stated reasons, and that defeats the purpose of keeping the 4wd unless you find a 4wd f800. I went though all the trouble because it had sentimental value to me. And for what I scored the 800 for it was cheaper then fixing the brakes and other problems the 600 had. Good running 429’s can be had for a song and will be more or less a bolt in application. I have invested countless hours into my swap over the last 5-6 years (still not “done”) so that’s something to consider too. If you count on using this truck at least a 429 could be swapped in with a couple weekends worth of free time if you had all the parts and pieces lined up. This is a link to my truck.
Good luck!
