[mickmate]

Measure the holes you have. It looks like the 1.5" hole with 5/16" holes on a 2 1/4" spacing. That will make it fit the original style Girling masters or a Wilwood update in whatever bore sizes you need to match your calipers. Are you using E type brakes? Standard number is to have 7" from the floor to the pedal pad center. I have a lot of drawings and numbers for these if you need any info. We're putting a floor mount original style pedal box in Jeffs car right now that has the back of the box attached to the frame extension you show in your picture.