One of the guys I roll with has his 2003 supercharged (by Kenne Bell, IIRC) and his NV3550 has held up to crawling, mudding, and plenty of stupid moments. I'm pretty sure between that, the slight bore, cam, exhaust, and a few other small things that he is around 360hp. Mine has held up with 270hp at the wheels. I think the same transmission was used in some of Dodge's half-tons too, FWIW.