I'm thinking about buying a cobalt SS/SC but I read there interals are only good to about roughly 300 horse. What about the interals of a SRT-4? How much horsepower can they had before they become unstable? Cause 300 is not alot of horse before I have to go in and change things internally. That might change my mind about buying a cobalt. Do you guys and gals understand where I'm coming from?