OK, I know that I have asked this question before, here and over at corvetteforum so bear with me. Say a guy wanted to free up the exhaust on his, oh say 1981 corvette and he thought that headers, a free flow cat. convert. and mufflers was the way to go. Say he wanted to keep the stock sound without sacrificing performance. If anyone here were going to do this what brand of products would you recommend this person to buy? In other words what products would give him the best bang for the buck? Or should I say which products are best, he wouldn't want to put just any old product on his Vette. What would the performance difference be with and without headers (changing caT. & mufflers in both cases)?