Guys, with all due respect. Check the picture that Gregg posted. Those babies will easily support 700hp. And it's not too much work to get them to fit. It's not a walk in the park either, but with MT it's very doable.
2.7 GT28 Eliminators do fit as well, with even less changes required. We have a car with those locally, hopefully should go in for tuning when spring comes. Power still remains to be seen, but I'm thinking 650-700.
Pic:
Placing turbos on the sides also has been accomplished.
It all depends on how much you're willing to spend (and/or how good you are with fabricating).