I am supposed to buy used ceramic coated plog and crossover from someone on another site. someone on that site said there was a group buy on headers HERE so I have a few questions. Are they gonna fit my '07? Can I install them myself? Can I use my ZZP DP instead of the one that comes with the headers? I ask because I need to be able to pass emmisions. Sorry if I'm a LITTLE off topic. TIA depending on answers I may be interested in these headers instead.