Hate to open the Mustang can of worms again, but Im gonna.... I would be REALLY dubious about taking the word of the Cobra forums as gospel when it comes to slips. I dont doubt the slips, I just completely doubt the definition of "stock"...
I remember this argument happening MILLIONS of times on the Corvette Forum with both Mustang and Supra guys. Because both of those cars see significant gains with "free" mods, these guys will often claim "stock" when they "just have" intake, exhaust, headers, pully, pulled hoses, down pipe, increased boost, etc. You may laugh, but it's true.
I had an extended argument with an F-Body guy that "headers" does NOT friggin count as stock.
These guys tend to be in an eternal effort to inflate the image of the car. It's the same with the Supra. When was the last time ANYONE referenced STOCK Supra times? The excuse is always that "well, no one is stock since BPU is so cheap and easy". That makes the whole argument pointless.
I wouldn't believe those mid 12's slips are from a bone stock car unless I could inspect the car myself.