Old PU/ Japanese chassis

This isn't a IHC-only topic and it isn't always popular, but..
I've successfully swapped frames on three old pickups using Japanese running gear and electrics.
These conversons make exceptional work trucks in my opinion. Great gas mileage, stylish, serviceable
and very dependable.
I'll talk about my 1938 D-2 on 2000 Nissan Frontier because we're on the IHC website.
Before you tell me I ruined the D-2 please know that a previous owner had inserted 1970 American Motors station wagon running gear under it.
A friend of mine owns a tow yard and had a 30k mi Frontier, rolled.
Without putting a tape measure on anything I bought the Frontier.
It took two weekends to tear apart the two trucks to see what was going to fit where.
Luckily, 1938 IHC D-2 has a relatively wide frame compared to similar vintage pickups.
The D-2 cab, believe it or not, lined up with two of the Frontier cab mounts!
The hardest thing to do on these conversions i think is to get the front tires centered in the front fenders. I failed in this regard, my front tires ended up about 3/4 inch too far back. No one ever noticed!
Once the cab is bolted on--I always use the donor Japanese cab mounting system and brackets--you can begin sectioning the radiator support.
Besides getting modern suspension, disc brakes, p/s steering, fuel injection, etc, you get a completely different frame layout.
For one thing Japanese pickups have everything "squashed" towards the front of the vehicle. It's your job to push the radiator-fan-engine-trans etc back.
I just cut the front motor mount brackets from the frame and after d/c the driveshaft and exhaust, move everything back about 8-10 inches. Of course sectioning of driveshaft and exhaust follows. Trans mount on floor jack until final location is reached.
The other frame layout difference are the kick ups over the front and rear axles. Once the D-2 cab is bolted to the Frontier frame, it's obvious that this D-2 is going to be much lower than stock. I think that's cool.
Old pickups of this vintage hang all front sheetmetal, radiator, radiator support, headlamps, etc off of the front radiator support bracket. It's just a heavy tab of metal usually with two big slots in it for the radiator support located in the front crossmember.
Obviously, Frontier and other Japanese trucks don't do things this way so you have to install your own radiator support bracket. I find a big chunk of at least1/4 inch thick and plasma cut my own bracket after locating where it needs to be.
Once the radiator support bracket is installed then the amount of radiator support sectioning can be determined.
Use strings, tape, line of sight or all the above to determine how much radiator support to section. This is one of the few places where cutting a little too much isn't bad. You can shim it up where you need it.
You know the front sheetmetal, etc is installed correctly when the hood fits and all the body lines line up correctly.
My D-2 was an ex-Marines 1/2 ton flatbed, it never had a pickup bed on it.
I had the bed and fenders from a 1935 Chevy pickup. That's what went on it. It looked good.
I cut the firewall out of the Frontier and installed it into the D-2. The previous owner had already cut the firewall to make the Rambler six fit.
By grafting in the Frontier firewall, all the mounting points for pedal hangers, column, gas pedal, e brake, etc are present. The Frontier stuff just bolts on now.
Immediately you have brakes.
Gotta extend the steering shaft then you have steering.
Accel cable just screws on.
E brake assy just bolts on, have to shorten the cable a bit and then you have e brake.
The plastic pod around the steering column is trimmed to fit closely around the dash.
After double checking, the driveshaft is shortened. I don't send them out, i just cut them on a cut off saw. Before welding up, I rotate in a piece of channel with a piece of wire to check for run-out and that u joints are lined up. Once I'm satisfied, I weld it.
Shortening exhaust is much easier.
It takes a afternoon or so to make the cluster fit the dash. The cluster is just plastic, cuts with a hacksaw.
Once I find a suitable place for the computer, it's time to start wiring.
Since I labeled all the Frontier wiring connectors, it's just a matter of plugging everything in.
Once the battery is relocated to the bed and connected to the system, it is very satisfying to turn the key and hear the pickup start.
Lots of little details but this project took me about 4-5 MONTHS, not years.
Immensely driveable, very quiet.
Hvac and wipers are for another time...
This Frontier was standard shift which presented another problem. The clutch master was located in a place on the Frontier firewall OUTSIDE of the D-2 firewall width. In other words when I cut the Frontier firewall to fit the D-2, it couldn't include the clutch master because the D-2 firewall is atleast 10 inches narrower than the Frontier.
Relocating the clutch master and reconfiguring the pedal hanger linkages probably took me a couple of nights.
Because of this problem I recommend using auto trans Japanese donors. But if I could overcome this minor annoyance, so can you. Cable clutch Japanese pickups like Mitsubishi might be easier in this respect.
Wheelbase is also a concern. My Frontier wasn't a extended cab truck. An extended cab Frontier would've fit wheelbase better.
However, with removable rear fenders you can bolt them on wherever you need them to adjust to the different wheelbases.
I just loved this truck, drove it everywhere. Had to sell it to pay for a anniversary ring for my wife. (Her idea). But she's right, she's more important than any old truck. I built two more after that using what I learned a 1941 Dodge on 1988 Mazda and a 1939 GMC on 1987 Nissan Hardbody.

I really like your way of thinking and making it better. I believe that it is the old styling that is the charm, not the pathetic old IH running gear that is not compatible with the changing times. I would not give too much regard to many of those persons who will certainly jump on your case about “Keeping it original”. For some of them, I am convinced, this is their excuse for never finishing anything, because, unless one has some NOS, it may not be possible to build to original.
I never run the IHC OEM running gear, we change everything to Cummins B series in both the 4bta and 5.9l 6bta and the axles we use are always DANA. Everything leaves here as a 4X4 with disc brakes.
Once again, good on you. I know this will work out and you will be very pleased. BTW. This will not be the first time that IH has had NISSAN power. The Scout used a NISSAN Diesel.
This hobby has become very costly. The first thing that anyone should do is to check their savings. Kiss it good-bye and have a nice day.

Thanks. Yes, I forgot to mention this conversion was inexpensive. I had something close to $1000 in the D-2, another $300 or $400 in the rolled Nissan, and let's say another $500 in consumables, tires and battery.
I had purchased the D-2 long before, so the only outlay at the time of the build was less than $1000.
The man who bought it on eBay showed up on his motorcycle, stowed the motorcycle in the back of the pickup and drove it home.