A short wheel base Dakota is pretty short, but adding a few inches between the wheel base would not be that difficult, the Dakota frames are nice straight boxed front segments and decent rear channel sections.
Using the standard Dakota wheels, the track width is about 60". By the time cars & trucks got into the late 30s, the 60" wheel track isn't too bad. Match up something close to the wheel base and your in business.
When I put my 48 Plymouth business coupe on a 90 Dakota Chassis, I used nearly the whole truck! My doner truck was a standard cab, long box, so I had to shorten my frame 8" (you would probable have to add 4" to 6" to your wheel base, or modify the car body. to fit your wheel base.
I parked the coupe & the Dakota side by side & removed the nose and pulled the drive train off of both. I removed the Dakota box & shortened the frame to match wheel base. I took the extra length out between the rear cab mount and the fuel tank location. The factory splice could be another location to change the wheel base.
I trimmed the cab roof & rear panel off the Dakota cab, I discovered if I moved the cab floor back 7", the coupe firewall & the truck firewall would match up. I made cab mounts & moved the floor & firewall back. I the process of measuring, I discovered the Dakota cab, at the firewall was 8" wider the the 48 at the firewall. At the back of the door, the Dakota was 4" wider then the 48 (this is the widest part of a 48 Plymouth business coupe).
My coupe body was pretty rusty, and the floors were shot. (I live in Northern IL, shot means nearly nonexistent, I have picture proof
) I reinforced the boxy shell and removed it from the coupes original frame. With it hanging on my cherry picker, I trimmed back the Dakota firewall & rockers until the 48 body sat down on the frame. At this point, I had to trim off the rear of the Dakota frame. I had to remove the rear crossmember, and rails to just behind the rear spring hangers. At this point, the 48 body set down on the Dakota frame right to my reinforcing. From that point, after squaring everything to my satisfaction, I built new rockers to attach the Dakota floor pan to the 48 body shell and I built a new rear frame crossmember and rear body support and bolted them together. The nice thing about using the Dakota floor pan and firewall is that everything is still in the same relationship it was on the truck. I used the column, the seat, the seat belts (I had to move the rear anchor point in 2" on each side). I also moved the motor & trans back 7" to keep everything there in relationship. That only required modifying the motor mounts on the frame, and moving the trans crossmember back. There is a lot more clearance on the sides of the motor with it moved back 7".
My car is a business coupe, there is not, nor ever was a rear seat. Therefore, the height of the rear floor is of little importance to me, its just storage. The process of shortening my frame where I did, removed the front two box mounts, and the rear two box mounts, but the 2nd & 3rd sets of mounts were still present. Using a large piece of cardboard (think appliance box) I could lay out what I would need for the floor pan behind where the cab floor ended. What I discovered was that the truck box floor would nearly complete the rear of the car floor!. Besides that, I could cut a gas door into the side of the car, and keep the Dakota fuel tank in its original location, and I could bolt up the center box mounting bolts and the box floor would clear the tank. I would have to fabricate the area around the fill tube, but that was much easier then fabricating a floor pan and bracing. I would also like to point out the front box floor crossmember would sit on top of the rear of the cab floor.
So I hacked up a pretty nice Dakota box to get the cab floor, but don't worry much, I reused most of the box sides for patch material. I used my cardboard template to lay out the floor pan trim lines. The worse part was I had to split the box floor into a front section and a rear section to fit them in the car. The front section fit very nicely, the rear I had to trim a bit to get fit into place. Once the box floor was bolted into location, I joined the 48s wheel wells and quarters to the Dakota box floor, and spliced the floor sections back together.
I completed the floor part of the build by adding a 6" vertical plate between the cab floor and the top of the box floor, and added the fuel fill door (from the Dakota) and built the fill tube enclose.
I also built a vent box to replace the Dakota one, and sealed it to the coupe cowl. I will probably be redoing that in the near future, it works, but I didn't like how it came out. Inside the vent box is the Dakota wiper system.
I had to fabricate a radiator and front fender support, and I fabricated new inner fenders. I used the Dakota V6, 5 speed, the entire frame and suspension, the Dakota radiator, heater box, steering column, dash, wiring, computer, exhaust, seat, seat belts, wheels, and even the door handles & latches and window cranks.
The whole project took about a year and a half, working mostly outside. Probably nearly 1/2 that time was spent patching up the rusty body I started with. A lot of the fabrication was more or less cutting pieces to fill holes and welding them in, but there was a lot of head scratching going on as well, so that the fabrication could be mostly making little filler pieces.
I probably have as much money in redoing the entire Dakota brake system as there is in the rest of the car. The car has been on the road for 3 summers and its a fun ride.
I have pictures of this process, from after the body has been attached to the frame on (there is probably 40-50 pictures of the build process), but I can only post them 1 at a time here, and I don't have time for all that. So here is the status of the car at the beginning of last summer (right now its burried in a snow bank). Gene
