Well my trusty old D70 has had a hard life and it's on borrowed time now I think. Starting to get a vibe under acceleration, especially with a load, and has been noisy for a while. It's been behind the 5 spd for over 60k and has over 240k on it total, and the limited slip still works.

I would like to just rebuild it, but I don't have time for it. So a swap is due, and I was always planning on a D80 but was just seeng if anyone has done/heard of putting an AAM in. I guess you would need 3rd gen wheels to cover the brakes, beyond that I haven't looked into what's needed. Thoughts?

Also, to recap, the D80 is a bit longer and requires larger u bolts, right? Yoke is the same? That easy?

 

Not to hijack your thread, but How much can a D70 handle? Everyone I talk to says its a ultra strong 1 ton axle used in F350 and E350's yet I personally know many CTD owners including myself that have broken a pinion tooth on them, After My 2 pinion teeth shot out of the diff cover I was also looking for a D80 until one of my car transport Russian customers rolled his mint 2002 trying to pull a loaded fiver with 3 sprinter vans on it and he sold me his disk brake D70 for >$200 so that's what im running now. Is doing things like this going to kill my new D70? It was harder to pull this sand than it is my 32' toy hauler loaded!
2 YD wet sand for a play structure in the back yard:

 

It is a pretty stout unit behind an auto I'd say, but when behind a direct clutch it can't take the abuse as much. I have had countless loads like you have pictured between firewood, fill, gravel, machinery, etc. and lots of medium-heavy trailer loads, plowed, etc. I also changed fluid every 25-40k with RP or Lucas 75-140. I think then only reason I"m having problems now is almost 2 years ago I got stuck in some deep mud/water and blew the pinion seal out on the way home (70miles) and lost almost all my foamy fluid. Made it another 15k miles since then.

 

you should use the Dana 80. It would bolt in with factory parts. Not sure what gear ratio you have. Just remember the 80 has 3.55's and 4.10's. the aam has 3.73's and 4.10. make sure you get the right ratio.

 

I ended up going with an 80. The 70 needed bearings all around (except hub bearins were tight) but I was impressed with the internals otherwise, they look great even with all that rumbling it was making. No chips, uneven wear marks, cracks, etc.

 

My first '96 2500 with the Dana 70 limited slip started popping and snagging at 170,000 miles. I thought for sure I was going to have to rebuild or replace. Before I did, I changed the gear oil and added twice as much friction modifier as is called for. Sold the truck with 280k and never had another problem. Hauled a 24' goose neck and a 20' skid steer trailer loaded 2-5 times a week with no issues.
I had air bags on the back and I believe they help more than just helping your springs. I never had to replace anything on the front end. No ball joints, no steering parts, nothing. I'm going to bag my new one for sure.