Just wondering if any on this board have also worked with or are knowledgable on the ls1. Reason i'm asking here is you guys are usually honest and i can get a more unbiased opinion than on an ls1 forum. I've been visiting ls1tech.com recently and these drag racers are making nutty power. Their claiming just basic stuff like bolt ons and a cam will net you over 400rwhp. What experiences have you guys had with the weaknesses of these engines? Some are claiming up to 650rwhp on stock internal engines with turbo set-ups, but i suspect they are also using meth injection or 100 octane fuel. Its seems that most add comp 918 valvesprings to prevent valve float, and if they want to rev over 7k to upgrade the rod bolts. Are these high quality engines, or are they problematic like some older products? I've only driven 5.3 and 6.0 liter versions of the 3rd gen motor in trucks and liked them just fine, the 5.3 idled like my lexus, and pulled about just as hard, the 6.0 pulled harder with a manual in a 3/4 ton 4 x4. Are these guys making them out better than they are? Are there secrets they don't mention? Or is it a really fantastic motor?