Meckes-wreckus

I just recently got a 1979 Toyota Sunrader.. Planning on swapping out the 1/2 ton rear axle for a 1 ton full floating axle.. My only problem is Im not quite sure where to start.. If I get a newer axle, will I be able to convert it to fit my older model? Any suggestion on what to get an axle of of (make, model,ect)m Thanks in advance.