Folks, I need some help deciding about a new exhaust option. I've been looking at the Ambush and I certainly like the price point. I've read the only threads I could find and people seem to like them. They sound pretty awesome! They seem to have a few different options and I just don't know enough about exhaust to decide. They have the Ambush specific for customs LSD or RSD, step tuned with or without heat shields, and then they list a difference between performance and racing. What should I be looking for?