Is the diameter of the 87-88 TC front brake rotors the same as the 87-93 mustang 5.0's?
Yes. The only major difference is that the TC rotor has the reluctor ring for the ABS system.
They should fit a '87 Cougar too with the TC spindles, right?
Yep.
Cool, my Dad scored a '87 TC for $300. Of course the rearend is going into his '87 XR7 and I was curious on the fronts. Looks like the rearend is a fairly decent swap based on the tech article. Anyone use the CHE control arms?