Before you go nuts, I USED to sell H2 parts. I have 2 H2's but I sold the business. Been doing this on Vettes, SUV's, PT's etc for 50 years. I have always been the guinea pig for items I wanted to sell. I test them for quality, value features and benefits BEFORE I take them on in my warehouse.
Concerning Exhaust, I have tested Magnaflow, Corsa, Borla, Bassani, Xtreme Flow, and custom. The results are very clear.
Bassani and Corsa are BY FAR the best available. I didn't even sell Corsa. Here's the results UNBIASEDLY:
Bassani - 11 horsepower; 92 decibels; approx. $575. Great sound
great fit, no welding, very durable; excellent quality
Corsa - 10 horsepower; 94 decibels; approx. $650. Great sound;
great fit; very durable; good quality.
Borla - 7 horsepower, 91 decibels; approx. $695; hisses at 3000 rpm; fair fit, fair quality... too much NAME, too little quality.
Xtreme Flow [SMA] - 8 horsepower; 91 decibels; approx. $650;
needs welded, not complete; I sold them only because we got requests for them. Dennis is a good guy. Their product isn't.
Magnaflow, Flowmaster, Gibson etc.....save your money.
I hope that wasn't too commercial. I don't sell them. I'm just honest about them. Buy Bassani. If you can't find them, buy Corsa.