I ran an 04 Cobra vert with just an intake I beleieve at the track. He went 12.4 on stock street tires... Needless to say I wouldn't be messing with that car on the street but I also don't have a HCI setup.
The Mach 1s you don;t hear about unless you pay attention to Mustang racing. Lots of Machs did well in Factory Stock, and a lot of those guys are going low 12s high 11s with simple bolt ons, gears and tires. I LOVE the Mach 1s. An all motor 4.6 car weighing a ton that will go 11s with bolt ons, tires and gears! Thats great!