I use the MM c/c plates and no, you can't use the strut tower brace with them. Then again, I also have the JLT intake which prevented me from using the strut tower brace in the first place.
Tell that guy at Pep Boys he should stick with soccer-moms car instead of trying to give advice on aftermarket mods for Mustangs.
If I'm reading this right the OP has a 96 Cobra correct? If so then he can too use the MM caster camber plates and use his strut tower brace. I have both installed. MM caster camber plates, STB, griggs coil overs-lowered of course. Damn near perfect alignment.
You sir seem to have a 95 which is probably the big difference.
Sorry to hijack just wanted to let the op know. If indeed his car is a 96.