Need help deciding on which diesel to swap

FlatbedCowboy · Apr 5, 2018

So I was just given a 1968 International Loadstar 1600. It has a bad engine and has been sitting forever, but as odd as I am I love the look of the old beast.

My plans are to take the cab off the frame and turn the frame/flatbed into a trailer. Its a dump bed, so I plan on making that work with my tractor and use the trailer as a utility trailer around the ranch.

I would like to take the cab and put it onto an excising truck frame and engine platform. I want something equivalent to a F450 or 1.5 ton running gear but at a minimum I will want a dually. I would like to not do a cummins, because of the cost.

I have instant access to 2 different 7.3Ls. One is a 1995 F350 with 299K and has a starting problem and the other is a 1996 with 180K but has been used super hard its whole life (former construction truck). Both these trucks I could get for under $2000 easy. Im not super hot on using one of these though as they take quite of bit of cash to make any power, are non-intercooled, and slow.

The other trucks I have been looking at online are 1990s-2000 6.5L GMC 3500HD trucks. I like the fact that they have larger frames, are 10 lug, and cheap-ish. But I have read that they are dogs and super slow.

I want this to be like a highway trailer totter that would get used a dozen times a year to pull loads of around 16K. I would like to do at least 70 mph ( I know gearing helps but you have to have power to get it rolling). I also want to lower it as low as I can to the ground so 2wd is preferred. Also CHEAP is what Im after.

Any other ideas that will help guide my search for a suitable donor?

Thanks

gwunter · Apr 5, 2018

Dt360 or 466 and get this party started!!

threegenpowerstroke98 · Apr 5, 2018

What he said, a dt swap can be a fair bit cheaper than a cummins swap, and a 466 would fit in that ih hood nicely and big good power and gobs of torques with basic mods like pump tuning and a turbo. Are the 7.3s manuals or autos? The 7.3 with some basic mods like stage one injectors, tunes maybe turbo etc could be a good powerhouse. I wouldn't bother with the 6.5, 7.3 runs laps around them all day imo.

sootie · Apr 6, 2018

dont even consider those old GM engineering disasters. They were some of the worst work trucks to ever grace the pavement.

FlatbedCowboy · Apr 6, 2018

I would like a DT360 but those are harder then hens teeth to find around here. I think the closest large truck salvage yard to me is like 4 hours away.

My main problem is the whole drivetrain/suspention/frame etc is completely shot on the loadstar. Least shot enough I dont want to use the current setup. Thats why Im thinking I need a whole donor to just swap cabs with.

FlatbedCowboy · Apr 6, 2018

threegenpowerstroke98 said:
Are the 7.3s manuals or autos? The 7.3 with some basic mods like stage one injectors, tunes maybe turbo etc could be a good powerhouse. I wouldn't bother with the 6.5, 7.3 runs laps around them all day imo.

The 299k one is auto, the other is a 5spd.

I had a '99 7.3L before it burned to the ground, so i know how to work on them, but once you start with mods it never ends it seems. It seems the horsepower return on cash investment is marginal.

But Im thinking since the 5spd is also a 4 door long bed, that would give me the long frame look Im after. When I drive it though, it just feels plain wore out and top speed towing with it is like 62mph.....

But maybe by the time I swap it all over Ill have found a better engine

gwunter · Apr 6, 2018

What region are you from?

FlatbedCowboy · Apr 7, 2018

gwunter said:
What region are you from?

Im in southwestern Idaho, Im about an hour west of Boise

ghohouston · Apr 7, 2018

FlatbedCowboy said:
The 299k one is auto, the other is a 5spd.

I had a '99 7.3L before it burned to the ground, so i know how to work on them, but once you start with mods it never ends it seems. It seems the horsepower return on cash investment is marginal.

But Im thinking since the 5spd is also a 4 door long bed, that would give me the long frame look Im after. When I drive it though, it just feels plain wore out and top speed towing with it is like 62mph.....

But maybe by the time I swap it all over Ill have found a better engine

That truck that feels worn out with low top speed, probably has 4:10 gears, with a 5 speed, right? Not worth a damn for highway driving. Those gears are the issue.

FlatbedCowboy · Apr 8, 2018

Right, I know the 5spd sucks it always feels like I needed one more gear. My burned up truck had 4.10s and was a dually also but seemed to at least get along the highway half decent. Maybe it's just cause it's an obs vs the 99+ engine

ghohouston · Apr 8, 2018

Was the super duty an auto or 6 speed? Tire sizes also play a role

FlatbedCowboy · Apr 9, 2018

ghohouston said:
Was the super duty an auto or 6 speed? Tire sizes also play a role

My old super duty was an auto.

I think Im leaning more towards using the OBS with 260K on it as my donor.

Next I have to decide if Im going to cut the cab off and marry the firewall to the loadstar or if I am going to have to do it the hard way.

FlatbedCowboy · Jul 2, 2018

Well here she is, 1967-ish Loadstar 1600. I still havent decided what truck frame I want to put this cab on yet. Still looking at all my options. I think the patina and odd door make this cab pretty ratrod eligible; just something different not everyone has.

IMG_1139

IMG_1149

IMG_1140

gwunter · Jul 2, 2018

Cough....dt360.....cough cough

Anxious to see where this goes.

Sent from my SAMSUNG-SM-G900A using Tapatalk

psduser1 · Jul 2, 2018

That could be a really cool project! Mechanical engine all day!

FlatbedCowboy · Jul 3, 2018

gwunter said:
Cough....dt360.....cough cough

Anxious to see where this goes.

psduser1 said:
That could be a really cool project! Mechanical engine all day!

I know I know, Im trying!!

I found a whole truck; DT360 with a 6 speed (unsure of what kind) in seattle for $3500 which is the same price as the locals want for just the engine. But 3500 is about twice what I want to spend on a power plant.

Or theres a DT466 right near me for pretty cheap with an unknown Allison tranny for a decent price.

My biggest concern though is Im fairly certain Im going to be putting this cab on a 1996 F350 dually drive train and Im not sure the DT466 will play nice with the front end. I may end up just using the 7.3L from the OBS to get it moving along and then when I find the right engine/tranny combo swap them out.

Decisions, decisions....

Inline6359 · Jul 4, 2018

I always wanted to do something similar. Either with a 8.3, 466, or 408.

markfuga · Jul 11, 2018

I'm in the process of swapping a 1963 International V-liner onto a 1984 International S1900 chassis with the DT466. I found the 84 cheap but preferred a 1993 to 1995 which has the "P" pump (last years of the mechanical injection engines). 84 to 92 were the years of the inline MW pumps which are good, but the P is better. There's write ups on the web for turning up these pumps. I did that and it woke the truck up! Entirely different than when I drove it home. I say look for a 93 to 95 International to swap onto. Much easier to move your cab onto a 34 inch wide frame that's already properly setup with it's engine and trans, driveshaft and rear axle than modifying everything. I really like the sound of the older mechanical DT's versus the electronic that started in 96.

FlatbedCowboy · Jul 12, 2018

Hey markfuga,

That sounds pretty sweet, I have been doing some searching around and it seems a point of contention on the pumps MW vs P etc.

I have kinda changed gears on what chassis I want to put this thing on and I have started my search for a mid '90s F-superduty which is like today's F450s. They have 10 lug rims and I believe a DANA 60 in front and 80 in back and a 34" straight rail frame. But most came with a 7.3L so it seems Ill still either be doing a 7.3L or have to find and swap something else.

I have shied away from swapping onto a medium duty truck, mainly because I want this thing to be as low to the ground as possible and I think it would be harder to do with a larger truck and thicker frame rails. Plus possibly more expensive. Not that I havent ruled it out yet, but if it came with a DT360 I may reconsider.