I am doing the exact set-up right now. From what i have found out to further AK98TACO is that you shouldnt use a 78' and 79' from a f150(1/2ton), f100, and full size bronco, but from a f250(3/4ton) is fine.
"Axles to avoid: 44RS 1978-79 F100, F150 and full size Bronco 44RS. This is a good axle only if left with the factory coil mounting brackets. Be sure to a void the 1/4 inch thick inner tube version. Price is average because high amount of these available."
What i chose to go with is :
"Suggested 44RS Axle for swapping using 8 lug bolt pattern: The F250 44RS 1977.5 to 79 44RS axle. These years come with the larger 8 wheel bolt pattern and brakes. They also have a leaf spring mount and 3" diameter axle tubes with ½” thick tube walls. You can swap knuckles out if your looking for a different bolt pattern, see below note on this. These axle usually cost at least double of a 1/2 ton."
I am going to keep it full width also and keep the yota out back. My friend Dave has the axle now, but i am going to get it this sat. The WMS-WMs on the axle is 67 inches. So there is about 3 inches extra on each side. I was going to run 1.5 inch spacers on the rear so it is only 3 inches wider total.
This axle can be switched to a 6lug with 5.5 bolt pattern(same as taco) You just have to get some flat top knuckles from an early jeep full size axle.
Now for my question to you. I am going to run the 37 MT/R also. I totally agree with you, i have a set and I love them, and want them after the swap. So in order to clear the 37's what front springs are you going to run. I have heard that with a 3inch body and stock waggys, you could almost clear 39 swapers. I didnt really want to go much higher then that. Just curious to what your plans are.
Good luck with your search
All quotes from
http://77cj.littlekeylime.com/web_rs44.html
Brian