Dr.Jass
Pastor of Muppets
The Dakota axle, if anything, will be narrower than the original. As I recall, the "Daxle" is very similar in dimension to the F/M/J-car unit which is close to the '65-'67 B-body unit but wider by about .100". The '65-'67 B-car axle is 2½" narrower than the C-body axle used '65-'69 (except '69 wagons, which were even wider). The tires may fit, but not likely using those sexy BBS wheels. Like all Dakotas, they use a FWD-style offset.
The front will pose a similar challenge as track widths are usually pretty close F:R. A 2WD Ram 1500 frame/axle might be a better place to start.
On the engine location, I'd start with the transmission mount and work forward. The transmission's mount location is essentially ironclad, with only an inch or two leeway in either direction if you plan to use the original C-body body crossmember at all, and that inch or two may require quite a bit of fab work. The Dakota trans mount is much more similar to a GM-style mount than what you're used to seeing under older Mopars. If you plan on using the Dakota stub far enough back to use the Dak's original trans crossmember (which I don't recommend since that frame hanging down would ruin the profile of the car), then the only place to start with your measurements is centering the wheels in the wheelwells... and then you've got to live with the location of the engine, the trans and shifter location, etc. and make everything work around that.
Myself, I'd probably cut out the Dakota frame sections needed to mount the control arms, steering box, etc. and somehow work them into the original front subframe maintaining the Dakota geometry. That wouldn't be easy and though it's more work from a frame standpoint, I think it would be easier from the standpoint of engine/trans/shifter location. You could then work off the transmission mount and weld frame tabs where required to mount the engine. Of course, this option still leaves you in the dark from the front swaybar standpoint since it can't be widened effectively.
There are a ton of variables here. This may be one of the most-complicated swaps on which I've ever spent brain time. Short of chopping out factory unibody to fit the entire Dakota frame, modified to fit your wheelbase, I think even Chip Foose might think you insane. Even then, you're still facing a track-width issue.
Though one could say I'm lazy and be 100% correct, were it my project I'd probably source a set of '73 C disc brakes, leave the stock rear axle but get gears close to what's in the Dakota, and not worry about the ABS (I'm not a big fan anyhow, since its only real advantage is on ice or slushy snow). I wouldn't monkey with the suspension, either, save replacing bushings with some poly upgrades in the right places and maybe adding swaybars. I'd be happy with the 3.9 and NV3500 running in the car, with the rest of the car essentially stock. I might even do the emissions thing just for fun, converters and all, just because I could.
This is merely my opinion, but now that I've thought about it I think you're trying to go way too far with this. I don't mean to be discouraging--measure everything twice as I may well be wrong--but if I'm right you'll endure months of frustration making everything work geometrically (wheel spacers are not an option, period). Then you'll face even more months of wiring dilemmas. I know I'm being a Negative Nancy, but though I love the whole idea overall, reality is often an ugly stepsister.
The front will pose a similar challenge as track widths are usually pretty close F:R. A 2WD Ram 1500 frame/axle might be a better place to start.
On the engine location, I'd start with the transmission mount and work forward. The transmission's mount location is essentially ironclad, with only an inch or two leeway in either direction if you plan to use the original C-body body crossmember at all, and that inch or two may require quite a bit of fab work. The Dakota trans mount is much more similar to a GM-style mount than what you're used to seeing under older Mopars. If you plan on using the Dakota stub far enough back to use the Dak's original trans crossmember (which I don't recommend since that frame hanging down would ruin the profile of the car), then the only place to start with your measurements is centering the wheels in the wheelwells... and then you've got to live with the location of the engine, the trans and shifter location, etc. and make everything work around that.
Myself, I'd probably cut out the Dakota frame sections needed to mount the control arms, steering box, etc. and somehow work them into the original front subframe maintaining the Dakota geometry. That wouldn't be easy and though it's more work from a frame standpoint, I think it would be easier from the standpoint of engine/trans/shifter location. You could then work off the transmission mount and weld frame tabs where required to mount the engine. Of course, this option still leaves you in the dark from the front swaybar standpoint since it can't be widened effectively.
There are a ton of variables here. This may be one of the most-complicated swaps on which I've ever spent brain time. Short of chopping out factory unibody to fit the entire Dakota frame, modified to fit your wheelbase, I think even Chip Foose might think you insane. Even then, you're still facing a track-width issue.
Though one could say I'm lazy and be 100% correct, were it my project I'd probably source a set of '73 C disc brakes, leave the stock rear axle but get gears close to what's in the Dakota, and not worry about the ABS (I'm not a big fan anyhow, since its only real advantage is on ice or slushy snow). I wouldn't monkey with the suspension, either, save replacing bushings with some poly upgrades in the right places and maybe adding swaybars. I'd be happy with the 3.9 and NV3500 running in the car, with the rest of the car essentially stock. I might even do the emissions thing just for fun, converters and all, just because I could.
This is merely my opinion, but now that I've thought about it I think you're trying to go way too far with this. I don't mean to be discouraging--measure everything twice as I may well be wrong--but if I'm right you'll endure months of frustration making everything work geometrically (wheel spacers are not an option, period). Then you'll face even more months of wiring dilemmas. I know I'm being a Negative Nancy, but though I love the whole idea overall, reality is often an ugly stepsister.