converted to a stick

I have installed a tremec 5spd in my 67 mustang in place of my c-4. Now I am having problems with the brakes locking up after stopping a few times they pump up and the brake pedal arm presses against the cluth pedal pivot shaft this has actuallly applied the brake lights at least once. What I am wondering is if some good soul out there could maybe post some info If you have had a similar problem or post some pics if you have a car with the same set up that works right. I have factory power brakes with a granada disk conversion up front and used the factory pedal support to install the clutch pedal in.

Thanks for any help.

What is a pedal box. I am using the stock pedal support if thats what you mean. The pedals move freely its just the brake pedal arm hits the clutch pivot shaft where it intersects this contact actually applies the brakes and gets worse the more you stop.( i belive this is do to the brakes pumping up) Are there any differences other than the pedal size for the brake pedal from automatic to stick.