That blower is barely inferior to the Magnacharger and after talking to Livernois Motorsports about the most horsepower they got with a magnacharger, they said 550 rwhp. That was on a 5.0l stroker motor with heads, longtubes, and I THINK a cam. You could supplement this with water/meth or even nitrous to get to 600rwhp. It just wouldn't be one of those things where you could throw the blower on a 5.0L and then up the boost to make the numbers like you could with a twin screw or centri or turbo or TVS. The one good thing about the Roush that does have a one up on the magnacharger is the option to later change the head unit over to a TVS blower. Though that is IMO very expensive route.