Rear end & disc brake Swap

[project1968]

I am some what of a newbie, I bought a 68' truck last October and I have been working on it ever since. I am buying a 68' parts truck mainly for the bed but it also has 5 lug disc brakes and a 5 lug rear end. I was wondering if the 5 lug rear end will have a different gear than my 6 lug and is there anything that should be done to the rear end since it has been sitting for a while. I was also wondering about the disc brake swap. Will the disc brake spindles bolt in to my drum brake a-arms and what should I expect to do to the them aside from needing to turn or replace rotors. Any suggestions or tips will be greatly appreciated. This forum has been huge for me so far and I am loving my truck.