You can get 250whp out of a stock LS block...just make sure it's tuned properly. Detonation on boost is what kills most motors, the rods are good in excess of 250whp, and the cranks are pretty much indestructible. When you detonate, you can fry rings, crack ringlands, and put holes in pistons. Get some big injectors, a walbro 255lph intank pump, hondata, and a good tuner...you should be fine.