I honestly don't see the point in disqualifying a car because it had a pulley and tune. Instead of thinking of it like it's a GT with more power, think of it like all stock GTs just came with way less than they could have under OEM requirements. The car was engineered to make way more power because they knew owners would do it immediately, but delivered to make sure owners didn't kill themselves left and right. During the brief period where they considered re-engineering the car to continue selling it, it was going to be delivered with essentially what is the FRPP pulley and tune kit. I'd say there's an extremely low probability that there is a single durability test that a pulley/tune car wouldn't pass that a stock one would. Ford had cars making much more horsepower than delivered that ended up with many more miles than 98% of GT owners will ever put on (and that I know, only Jeff has definitely exceeded, with Ralphie nearing those miles). The odds of a regular owning exceeding that mileage and having something happen on the world's most de-tuned factory engine are next to none if the mods were from a competent shop. The odds of a regular owner doing something worse to the car than what the Ford cars went (go) through is literally none. Those cars exist just to be punished by the company employees, which is illustrated by the fact that virtually every single one crunched multiple or all body panels, some of them repeatedly.
Let's be realistic, Torrie's car is a tick away from 50,000 miles, the car has been turbo'd from the beginning, and it's made over 1000 for it's whole life with countless dyno runs, mile runs, etc. If you're disqualifying a 600 rwhp GT that has 6,000 miles and are trying to stay below the money that lower mileage showroom stock cars bring, you're limiting your market severely to the point where you may be waiting forever. A great deal of the cars that get some miles on them have been modified.