SW does sell adapters to hook up to stock cat-back/ factory connections that you can use on long tubes (not running cats). shown in link below- theoretically no welding -maybe on the passenger side, but I can attest that the ball flange on the driver's side works like a champ mating to the stock pipe set or on a Corsa.
http://www.stainlessworks.net/catalo...16/image/1294/
You can run cats on long tube headers if you really want to bad enough:
more recycled Z06 parts- LS7 catalysts using what was left of my SW adapter tubes (slip on collector fit).
