70 GMC Disc/5 Lug Conversion

[tallboyD]

I'm sorry if this topic has been beat to death, but I just want to make sure i'm going in the right direction. I have a 1970 GMC with drums all the way around. My question is what is the most affordable way to convert to disc and 5 lug...i was planning on buying a front disc conversion with drop spindles and booster, but the i'm a little unsure about the rear......can i directly swap 73-87 axles? what options do i have?

thanks for the help