So Mike, I started re-reading these to see if I missed anything, and twice you mentioned the use of the 94+ SN95 MC when using the PBR calipers. I know you say the 93 Cobra should work fine but it seems like maybe you used to prefer the 1 1/16" MC for that particular upgrade?
87-93Â Ford Fox Body Mustang Brake Upgrades
87-93Â Ford Fox Body Mustang Brake Upgrades
I'm not the author of that webpage.
I tend to recommend staying away from the 1 1/16" MC unless running the 94-98 GT/V6 setup. With the PBR and cobra setups, it tends to result in a hard pedal.
Basically, look at what the factory did from the start and model that. MC's are "tuned" for the calipers on the car to be a specific ratio in terms of MC bore surface area to caliper piston surface area.