I have a 1977 cj5 with 401/150/20 with the dana 30 and model 20 axles. I just shattered the model 20 the other day. A friend has a dana 44 out of a 75 cj5. Will this axle bolt right in? Do I need a pair of longer ubolts? Tried looking in the search but after 10 pages and nothing thought I would ask.

No, it will not 'bolt right in'. It's the same width as your AMC 20, but the spring pads are closer together. You'll need to weld on some new pads at the proper width and you should always use new u-bolts.

Is the front the same way? Spring pads need to be moved out? Thinking of swaping out both axles at the same time. Front I belive is a dana 30 also.

No, the front will bolt right in. In 1976 they changed the shape of the frames of the CJs. All previous CJs had frame rails that were parallel from front to back on 27.5" centers. In 1976 they changed the frame to make it widen out in the area between the axles where the transfer case is. The front frame rails are still on 27.5" centers, the rear ones are like 5 inches further apart.

Are the axles the same between the two years? To move the axle perches do you just grind them off and then reweld. Thanks for the help in advance. I guess the 401 was no match for the axle. I am suprised though since the 401 has been there since 85.

The axles in a 1975 CJ would have been a Dana 30 front with drum brakes and a Dana 44 rear with drum brakes. They should both be about 51" wide wms-wms (wheel mount surface).

The axles in a 1977 CJ would have been a Dana 30 front with either drum brakes or disc brakes and an AMC corporate model 20 rear with drum brakes. They should both be about 51" wide wms-wms.

If you have discs on your later Dana 30 and still want to use the older Dana 30 because the gears ratio will match the Dana 44, you can swap everything from the spindle out from one to the other and end up with discs on the 1975 Dana 30.

As far as the perches, you can get new ones for about $20 a pair. Much easier than trying to reuse the ones that are on there. You'll make a mess of them during the removal process. Been there, done that.

also the tube width is a little wider on the 44 or in other words the "u" of the u-bolt is wider on a 44 than a 20.