I might be able to get my hands on a set and was wondering about weight savings and possible track width change.

This would be for my '73 Dart.
I'm currently running stock '73 C-body 11.75" rotors, 2.75" dia. calipers and b-body adapters, but I might want to get something a bit lighter.

Track width is usually a problem on Darts as tire/fender clearance limits one from lowering the front end.

I actually 'gained' tire clearance because the C-body discs are positioned a tad more inward than the stock Dart discbrakes.

The added rotor diameter might help brakeforce but not by much I think.

Wilwood calipers typically have tiny pistons in them so you will most likely lose a bunch of braking force when you change over. Do the math and see before you do the swap. Otherwise you'll be back on here asking "why don't my brakes work anymore".

The deal went south the moment I heard the discs where for 4-hole wheel bolts instead of 5.
I know I can buy a 5-hole center to bolt in, but I don't feel like spending a fair amount of money on a new brake system when the current one is still functioning fine. Especially since I stepped down from a 1" diameter to a 15/16" master cylinder recently.
I also installed residual valves (which I didn't have before) and also put in a brake force limiter to the rear wheels as the brake bias has always been to the rear brakes on my car.

Andy you're right, in the recent past I've already done some comparing of piston diameters and found hardly any of the aftermarket calipers exceeded the 2.75" piston diameter that a single brake caliper has.

I still feel kinda sorry I didn't grab a pair of hardly used 13" DBA 5000 disc rotors out of the scrap metal bin from a local garage.
Didn't know the brand at the time but did see they were not cheap.
I thought they kinda knew what they had just removed from a 2000+ Mustang and perhaps were going to resell it, but found out later they just trashed them...