by cosvega76 » Thu Mar 20, 2014 7:54 am
First of all, what brakes do you have on your car? If you're using the stock '73 brakes (solid-rotor fronts), the 3/4" bore master on a '75 master will be okay. You should have no trouble mounting the booster to the firewall, but you'll need to fabricate a pin for the brake pedal. Power brakes uses the lower hole on the pedal, which - I believe - is a larger diameter than the pin installed for manual brakes.
Naturally, you'll have to fab some brake lines to mate from the master to the distribution valve. The front and rear lines may be reversed, though. I don't have access to master cylinder blueprints anymore. The factory also used a brace from the master cylinder mount to the fenderwell. Whether you really need it, I can't say, but some tubing, flattened at each end with a bolt hole, should be easy to fabricate.
Chuck