Clearance adjustment between the stop screw and the brake pedal level is specified as 3/32 to 1/8-inch clearance in Figure 8, page 12-01-06 of the Pantera Technical Information 1973 Ford Marketing Corp. Customer Service Div., Service Technical Communications Dept., Publications Section.
Every Pantera owner should have these factory manuals. There are three. The other two are Pantera Technical Service Bulletins and Ford 1971/74 Pantera Chassis and Body Master Parts Catalog. I told my girlfriend I wanted them for Christas 1999, before I got my Pantera, and showed her the ad in Hemmings Auto News, and there they were under the Christmas tree! They were inexpensive, and I think all the Pantera vendors have them in stock, but I've never checked.
It's better than waiting for an answer, just to know where to look, and just get the answer right when you need it. This bulletin board also has a terrific search feature, which pinpoints answers when you ask the question the right way. It's great to read up on how projects were done, and get inside tips before you begin the disassembly. A regular guy can do great mechanic work, the right way, with these tools!
(And a few of the normal tools, which are easily identifiable as "tools".... no mistake about what a "tool" looks like! Am I getting off the subject? Just kidding!!)