Daves right - roush is Stages 1, 2, & 3.
Saleen has the regular S281 - which is basically a GT
281 supercharged = GT with roots blower.
Maybe he has the S281-E which has like 425 HP or something.
Plenty of goodies on that one.
I hope he has one of these and modded the hell out of it b/c if not he is in for a surprise.