Small bolt to big bolt pattern
Doctor Diff & call it a day.
Exactly! :thumbsup:
Re-drilling the drums will just give you headaches. Rear axle flange material is lacking, it's been done of course and there are better and worse ways to accomplish the re-drilled flanges, so success depends on how you do it. But either way you're still stuck with re-drilling SBP brakes. Not so easy, relatively cheap, safety depends on execution. To me this is still a shortcut that will cause problems later.
Aftermarket kits are ok, but usually the only place to get at least some of replacement parts is from that company. Oh, and expensive to the tune of several hundred extra dollars. Most expensive way to do it hands down, usually pretty easy, safe. This gets it done right, but you pay for it in dollars.
Adaptors are probably the easiest and the cheapest way, and if you use billet adaptors that are ~1" thick (not the cast aluminum adaptors) they're plenty safe. But they will affect wheel selection, especially in the front. Even a lot of the OE mustang wheels won't have enough backspace for that in the front. Cheap and easy but it's a shortcut and it'll cause headaches with wheel selection.
Using the 73+ mopar disks in the front and aftermarket BBP axles with BBP 10x2.5" mopar drums is probably the easiest/cheapest/safest way to do it
right. All factory designed parts, everything fits. Replacement parts are available at the local parts stores. Cass
@DoctorDiff can walk you through everything you need, and can sell you
everything you need, one stop shopping for great quality parts. The '73+ Mopar disk conversion is cheaper than the Wilwood and SSBC conversion kits, even buying everything new from Cass. And if you can find an F/J/M donor at a local yard you may be able to do it cheaper than that. Same for the rear brakes. The 10x2.5" BBP mopar brakes can be bought new from Dr. Diff, or used on Ebay, or sourced from the local yard on most rear wheel drive Mopars up to around '91. Doesn't get easier than factory parts, factory engineered and tested so about as safe as you can get, and cheaper than the aftermarket kits available. More expensive than a re-drill or adaptors, but you won't cause you more headaches later.
