a rear axle q and a some opinions needed as well

[1974ChevyC10]

1st one-i was at mcdonalds before work and i guy with a nice 62 longbox rolls in-i ask about the truck and he says its a 62 and we talk some more and he says he is looking for a 5 lug set up to convert to disc brakes.well my eyes light up and i tell him i have a 78 im parting out and told him i would sell him the rear end or whole rolling chassis.he says cool and takes down my number and he is going to call me sunday.my question is from drum to drum how wide is a 78 12 bolt axle?


2 ones are as follows.i know of a couple trucks here for sale.one is 77 SWB that has been dropped-not really my thing and i have no idea how much it has been dropped-the reason im interested is as much as i like my truck it does have a terrible body on it but it has a good interior and drivetrain.the SWB im not sure what it needs as i havent looked at it yet.it does however have a straight body on it ive seen a pic of it.im thinking if i could get it for 1200 which is what the guy is asking put all my good stuff in it and primer it and drive it around until i can get more money and fix it up.the other truck is a 77 4x4 LWB which runs ok ive heard it run but the guy says it blows black smoke when running and he says its need a carb which if thats the case fine ill buy a new one.the truck is in good condition in and out and im told the 4 wheel drive works good but they wont budge from 1400 even with it needing some work.which do you think i should get and please lets not start a 4x4/stock vs lowered war here if we could.thanks for your opinions