I ended up using a stock '77 Disc/Drum prop valve, although I put an adjustable pressure regulator on the line going to the back brakes. I have a prop valve made for a disc/disc car, but it was gonna be a huge hassle to install...so I decided to try it the way I have it now and I was happy with it. The master cylinder is one that is used in the '76 Corvette. I can't remember if the size of the piston is 1" or 1.5" or what. I went with that one because it is a near bolt-in(needed the mounting holes elongated slightly) and the ports are facing out like the factory M/C. Like I said before, it worked OK with this attached to a factory vacuum booster, but the brake feel was hard and it took more effort than I liked to activate the brakes. Not horrible, but it felt like manual brakes. The Hydroboost corrected that and now they feel very nice. Lotsa work to get 'em where I wanted 'em though.
I think the part of the kits i dont like is that you have to still get a master cylinder and figure out the proportioning.If they are selling a kit as a "bolt on replacement" you should be able to use the car once making the changeover. other than that, the ones you linked are the same ones my friend put on his cougar and they work great.
Nobody says you have to change the M/C and the proportioning valve. I know there are people that swap in the rear discs and leave everything factory and they have said it works fine. I think they don't put them in the kit so you can decide what you need for your particular application.
I prefer the exploder rear discs. They have a park brake built into it, and it bolts right onto the 8" 5 lug rear end, for the most part. It's not a TRUE bolt-on, but real close: You'll have to drill out the caliper bracket holes to 3/8. you'll have to figure out a way to hook up the park brake (I never messed with park brake) the caliper bracket is thicker than the old drum backing plate; you'll have to either fab up or have someone make a pair of spacers to go between the axle bearing and the caliper bracket....IIRC, it was .200" thick and the same OD as the axle brg. I had an interference between the caliper bolt and leaf spring; I just trimmed the bolt down slightly and it fit fine (with 1/4" clearance). With a quick click on the search button I came up with these: http://mmb.maverick.to/showthread.php?t=4743&highlight=explorer+disc -and- http://mmb.maverick.to/showthread.php?t=18660&highlight=explorer+disc As an edit to the earlier posts, I found that the master cylinder from the Dodge pickup (I got mine for a '91 1/2 ton) worked perfect. Drill the mounting holes out to 3/8". Then you'll have to make the pushrod because the factory one is a little too long--which made the pedal a little too high--or at least it was for my taste. I'm 6'5" tall...and wear a size 15 shoe, so I don't care for the pedal being too high. I also used an adjustable bias valve I got from a circle-track supplier. It worked great.
The parking brake is a cinch to hook up. On the cable ends remove the retainer clip from cable. The three prong thingamajig. On the old brake drum parking cable lever cut the part the cable attaches to and wled it to the the explorer parking brake lever. Took all of 20 mins when I did it to my brothers car. Explorer is the way to go. I will be doing it to mine this go around!!!!!
