ok this may be a really stupid question, what would be the differance in buyin a CAT back system and buying turboII stock "Y" pipe for 90$ and these HKS univesal Mufflers http://cgi.ebay.com/ebaymotors/ws/eB...category=33636 and having a exhaust shop weld it all together????

 

those are not hks mufflers..they are a knock off