1000HP can be obtained without "drugs". Look at all the prostock tractor pullers who turn 1500+HP with a 400ci motor. With pistons that are flycut greatly, a really mean cam, good flowing head, lots of fuel, and 120+ psi of boost, and water injection; 1000HP could be obtained fairly easily. It all depends on how much $$$ you want to spend. Dave Mitchell told me back in the spring that with marine flycut pistons, one of his mean cams, and 40+ degrees of timing, my truck would have to ethered every time just to start it. I haven't built this motor yet, but he is correct. Just imagine how much air and fuel you could cram into a 5. 9 with compression that low. Another thought is the head. I was also talking to Kent back in the spring and he informed me of a marine head that flowed better and was stronger. With the products that are available for the 5. 9, there is no doubt that 1000HP can be easily obtained. If you think it hasn't been done yet, go watch Kent(Scheids) or Dave pull. I pull with both of them and I know roughly where I stand. These guys are way ahead of me. There's no doubt that they are 1000+HP.