There isnt much in this forum about single piece conversions for the AMC 20 differential. Here are a couple of points that may help you, I have just put Moser single piece axles into my 1970 Hornet.

1. AMC 20 differential parts in Australia are few and far between.

2. I have a 360 engine (350RWHP) and had an open carrier. The Australian Hornet AMC 20 differential is the V8 type (same as 1970 AMX and Javelin).

3. I had the car at the diff mechanics to fit a Power Loc LSD. Upon pulling the axles it was discovered one axle shaft was spinning in the hub (the common problem with AMC20 diffs). I decided it was a good time to upgrade the axles to single piece.

4. The research began and the clear message was you cant fit JEEP axles to the AMC vehicles. No problem, what are the options!

5. AMX Enterprises sells single piece axles (Moser) ready to fit the older AMC 20 diff for Javelins and AMXs (and Hornets). The axle part number for the 1970 cars is the same according the parts catalogue CDROM I have.

6. The level of service was great and knowledge of the axles from AMX Enterprises was beneficial, definitley worth talking to (Larry) prior to purchase and if you have any issues along the way. I had one question from the diff mechanic about the inner oil seal which I rang and asked Larry and problem was sorted in a couple of minutes.

7. The setup of the locker/ring and pinion (4.11 gears) was trouble free and the fitment of the axles required about an eigth of an inch taken off right hand axle for fitment.

I am very happy with the final outcome and recommend replacing that two piece axle if you need to. Have a chat to AMX Enterprises as they were very helpful to me.

Hope this helps