@johns truck, Ok, here's what I would do, find a vehicle that weighs approximately the same as my truck that uses a disk/drum set-up. Get the master-booster combo or buy it new. See what size lines it uses, probably 1/4" front and 3/16" rear. Get the disk brake set-up for the front and whatever new parts for the rear. Get the underdash pedal assembly and a big piece of the firewall. Don't forget the supports for the pedals and the brake light switch. Find or order a new rear rubber line. Now you have enough parts to begin the conversion. I'm sure you have a GOOD brake line flareing tool, 'cause you're going to need it. The lines are cheap; $3 to $5 each, but you'll probably need a couple of adapters in the rear. You get the picture. It is worth doing yourself, but no place to take short cuts! Be careful, you might have it pointed at ME if the brakes fail!
best wishes,
Les
