So if I understand right, the AD trucks have a washer/clip on the rod inside the nose of the MC to keep the rod from pulling out...that's the stop? If that's right then he will have to fab up a bump stop on the toe board.
After doing some digging, I found out a couple things about the original AD master cylinders. First, the piston end of the push rod is ball shaped (not just round on the end), and 2.) the end of the master cylinder has a sheet metal plate with a hole in the middle that the push rod passes through. This plate is held in place by a wire spring clip. So, the push rod is captured inside the master cylinder housing between the piston on the end plate. This set up is what makes it possible to adjust the position of the brake lever by shortening/lengthening the push rod at the clevis.
As 52Carl pointed out, the Corvette master cylinder does not have a captive push rod. Because of this, shortening/lengthening the push rod does nothing to change the position of the brake pedal lever. The lever goes all the way up until it hits the brake light switch no matter what. You still have to adjust the length of the push rod to take up the lost motion at the master cylinder so that your pedal works sooner than later.
At this point I think the easiest solution to my situation would be to buy one of those rubber bumpers that goes on the clutch arm, then cut one end down so that it sets the arm at the required 13/16" from the toeboard.
I thank and appreciate everyone's input on this thread.