Any of you guys that are running rear discs do you think it makes that much better braking than the drums. Is it worth the expense and if so which brakes are you running thinking of going with Tom's bronco parts kit. Also do I need to change my mastercyl. and proportioning valve running frt discs now.

I put jbg kit on my 79. when I did it I changed out the entire system with bigger calipers and bigger booster and m/c. so I have no comparison for you. but I will say the jbg kit is a tsm kit. made in USA. made in castle rock.

I've gone back and forth over the same decision. You can only use as much braking power as you can stick to the ground, and stock drums will lock up the rear tires without too much problem. The main advantage of discs is that they don't fade nearly as quickly as drums (only really of benefit coming down from the mountains, and not much of an issue even then) and they won't pack up with much or other gunk. The major down side is that the e-brakes aren't nearly as strong as using stock drums. I've mostly decided that it isn't worth the expense, although I may make the swap after I'm a bunch farther into my build. You won't need a new master cylinder, but you'll likely need a different proportioning valve.

I'm running rear disks on mine, and have put rear disks on all my rigs that have 35" or bigger tires. For me that's about where I think it starts to pay off. I've done the rear Caddy Eldorado conversions, the late '70s Lincoln conversions and the Explorer style. Hands down, the Explorer setup is the way to go.

If you're lucky enough to have the Torino style axle ends already, then the Explorer kit is @$400 to do everything, all new parts included. If not, then the kit is @$650. Those prices are for the Teraflex kits and you can usually get a discount off that getting them through http://www.4x4groupbuy.com You can put together your own "kit" by getting all the parts off an Explorer in the yard and redrilling the rotors, or just ordering redrilled rotors from Teraflex or Currie. Most shops want @$100 to redrill vs. @$130 for a new pair of them from Teraflex. If you want, you can get an EB rear housing with the Torino ends and swap everything over/build it for everything minus your center section, then swap it under/over on a weekend. Or have the torino ends welded onto your existing housing.

Most of the disk type E-brakes require more pull than the lever/cables are designed for on the EB E-brake system. The stock setup has a 2:1 reduction in throw, where the front cable comes in at the end of the lever and the rear cable comes in at the middle. If you reverse this you get much better pull on the rear calipers and they will hold.

That being said, a brake disk as it cools moves away from the caliper pads, basically reducing tension on the disk. A drum style shrinks as it cools, increasing tension on the pads. The Explorer uses a drum style E-brake setup, inside the rotor hat.
My $.02, Joe

thanks for the input i will let you know how I go with this now that I have some ideas