I'm a newbie... i have a 66 Coupe, wondering what people would recommend as far as converting the drum brakes to disk brakes... just convert the front, or all 4? who has a good conversion kit? should i go to 12" ?
If you wanna go kit, Stainless Steel Brake has a nice little front kit for under $900 that comes with everything you need. Photos of the install are on my website, click in my sig. I do all 4 wheels, but it really is not needed on a road car, the rear drums work fine.
If you are an average to heavy street driver, the 11" rotor setup is fine. Track use probably warrants something more like slotted rotors, bigger rotors, or special pads.
Rear drums get a bad rap. They work very well if properly maintained. Bigger drums are always an option as well as rear discs and special compound shoes or pads. Do the front disc conversion first and see if you want more.
If you have a 5-lug V8 setup, I think I would recommend the Stainless Steel front brake conversion. It makes less of a project out of the whole thing and gets your car back on the road sooner. I know- I did the '71 disc conversion ins. It works well but it took me 3 months (of spare time) to put it all together. If you have 4-lug, you could go SSB or 5-lug conversion with new spindles.
Get a dual chamber master cylinder. Power brakes are not necessary if you go with a 7/8" more MC like the '74 Maverick unit. Study up on proportioning valves and don't underestimate the pain of the hard lines.
As dodgestang said, Stainless Steel make a really nice 4 piston kit. But if you're on a budget, go Granada or Monarch, from 75 to 80. You'll need to use the Granad tie rod ends and Mustang sleeve, but it's pretty much bolt in.
On the down side, if everything needs to be rebuilt, it may not be worth it in the long run. Also you may have a problem with the left outer tie rod if your car has power steering. You'll have to call Mustangs Plus or see their web site foe a hybrid tie rod.
One last thing, the 4 piston set up works better then the single piston Granada.