Putting a modern rear axle in an a body?

Thanks for all the replys.
This line of thinking started from not wanting to pay $800+ for rear discs on my 8 3/4. I just ordered a welder so I will be getting back into the fabrication with a vengeance.
However I thought that if the axle from the jeep could be easily used in an A body it would solve a lot of problems. Obviously that is not the case.
I am going to secure a complete rear setup from a jeep and install it on the axle as is and then from there decide how to do the install permanently.
Andrew