I've only heard of a blown Mach 1 ONCE, and that was in some MM&FF magazine i believe. There really is no room to supercharge a Mach 1 under that hood, and they had to take out the tubing that ran form the airbox/airfilter to the hood scoop. So while the hoodscoop stayed on top of the motor, it was no longer functional when they were done. But they did successfully supercharge the car, but i dont remember their numbers.
I'd imagine a supercharged Mach would put down similar numbers to a supercharged 99 or 01 Cobra. So you might want to look up that...
If you just did a full exhaust (w/ LT headers), better gears, ported the heads maybe, and added Stage 1 or 2 cams...you might be putting down over 400hp, which CERTAINLY would give your Mach a kick.