You can use more modern type swinging pedals that don't go through the floorboard, which frees up room under the floor for the exhaust system, automatic transmission bellhousing, etc. Finding a pedal assembly from an aftermarket supplier that works with a frame mounted master cylinder has two possibilities- - - -slim and none. Either find the original pedal assembly or count on reworking the whole pedal setup for swing pedals. Are you going to run a stick shift or an automatic transmission?
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!