need some more help please! suspension

[ofnaman]

I am wanting to buy drop spindles for my '70 3/4 ton. I have not found any yet for the 3/4 ton's. My question is can I put spindles on it off of a '71 or '72 1/2 ton without changing the a arms? I know I will need to change to disk brakes and all of that stuff, but are the a arms the same? If not can I use 1/2 ton a arms without changing the crossmember? Anyone done this? Thank you.