LS1Nat

I made a few calls today inquiring about this kit. I was told the best thing about this kit is that nothing else is needed. No injectors or programming. It's a twin intercooler setup and they claim a 40% increase in horsepower. Which would put me in the neighborhood of 430 rwhp assuming my car makes 310 stock. Are these horsepower numbers possible? If so, is it true about not needing anything else? I'm just about to do it, but I'm wondering if I should kick out an extra $1500 and get the 8 lb kit. Your opinions and experiences are greatly appreciated!