I did a search, apologies if I missed info on this.

Frame up resto on 79 F-150 4x4, ford 9 rear axle, D44 front axle.

Front axle is in good shape, upon inspection the rear axle is a cobbled up unit with poorly replaced ends and basically worn out. Open unit, no limited slip. Needs complete overhaul, my preference is to replace it entirely. I don't think its original, but the front axle is.

I didn't plan on installed a limited slip but I added up the cost to replace the R&P, install/bearing kit/new axles/disc brake conversion, new bearing ends.

I then started thinking why not try to find a newer model truck axle that already has the disc brake setup. I understand that the rear ratio has to match the front and that the replacement axle may need another R&P. Another thought was to look into getting both front and rear axles out of a newer year F-150 or F-250, hopefully getting a front axle with a radius arm setup. Getting front and rear factory axles would yield the same ratio I think.

Changing spring perches/shock mounts is no big deal but I wanted to ask if there is info that may help give me info on candidates for replacment axles. If I just got the rear axle then maybe I'm not limited to just ford, maybe there is another mfg that has a unit that has the right width?

 

I found this as a start:
Rear End Widths

 

The Ford 9" is a great half ton rear end. Kits to convert to disc are readily available. Currie Enterprises has everything that you would ever need for the 9". I used a full floating 9" in my race car. It made 425hp. If you happen to break a pinion or ring gear, you just pull the axles and pull the third member out for service. Unless you will be using a high power engine, big tires, and four wheeling, your 9" will be awesome. I have a Dana 60 front and rear, but my truck has a 460, 39" tires, is locked front and rear, and is only used for 4 wheeling. If you do 4 wheel, you are much more likely to break a "Short side" front axle on the Dana 44 than a rear. If your trucks body is very nice, you could find a complete set of running gear from a '78 or '79 F250 Camper Special with the Dana 60's front and rear. Even with the Dana 60 front, I have broke three short side axles, one steering knuckle, and the output shaft of the steering box. I would stick to the half ton running gear unless you will be wheeling. Good luck on the project

 

Thanks very much. You're right about the Ford 9, I use one with T-Lock in my 57 Chevy 454/400, excellent piece.

Problem is that the one I have in the truck is beat to death, even the housing is suspect. I know that I can get replacements for everything, but in doing some research, it looks like a later model 8.8 with discs and 3.55 ratio (front D44 is 3.50) is almost a bolt-in deal at a lot less than basically replacing and rebuilding the Ford 9. Myunderstanding is that although the ratios are not identical, for soft ground it should not be an issue.

My use is not heavy 4 wheeling, I use the truck on our property and to haul a trailer sometimes. Most times just on the road with something in the bed. 4WD is just used out in the field if its soggy.

I'm lucky, overall condition of the truck is excellent. No rust, no tweaks. The rear axle is the worst thing I've come across and I reinforced the frame at the steering box . Taking it apart, 2 bolts were frozen, that's it, lol. Front axle is perfect, I'm replacing seals/bearings/balljoints more as preventive maintenance than anything else since the truck is down to the bare frame. My intent is to not buy a new truck, I have my own shop and tools to do everything from engine/tranny rebuild to paint. Would much prefer to have a nice older truck than a new one.

In light of my intended use for the truck do you see any showstoppers on the rear axle replacement to the 8.8? thanks so much for your input!

 

I don't see any reason that the 8.8 would not work. My brother-in-law really considered putting and 8.8 out of an Explorer in his CJ. He ended up using a 44 if I remember right. The 8.8 should be fairly inexpensive to buy. Post pictures of the build so that we can keep track

 

Sounds good, thanks again for your expertise. I'll get some pics up and get the garage set up here.

 

Couple of pics, this was the truck several years ago, not too much changed since then, but it was in need of a good resto. Specs: shortbed/400/C6/NP205, factory air, 9"/D44


Current condition is actually now a bare frame on pipe stands