Mine is spaced out a full 1-1/2" (38.1mm). I am using Halls master cylinder kit (Ford Mustang/SVO) and it has no issues with clearances.
For me, the pedal relocation took "my knees out of my mouth" and in combination with 2" lowered floor pans and a Taurus power seat track put me right in the correct position and gives me the ability to alter that on long trips for comfort.
At some point I measure the clearance between the inner portion of the front deck and the Master cylinder with a rigid foam board and it was in the vicinity of 1/2" to 5/8" clearance. All clearances in this car are tight and this is no exception.
That change, i.e., spacing out the pedal plate mounting, was a Ford "suggested modification". It works effectively for taller drivers.
I have found that in the case of the Pantera, sometimes what appears to be a very simple change requires a series of modifications for it to work as expected. This in my view is one of those scenarios.