I've gone with mod_stock. They were absolutely fantastic. They either come to you or if you want it done sooner you can meet them somewhere. They did mine in about 30 mins outside of a McDonald's an hour from me as I didn't want to wait until they were in my area. No issues with the exhaust and the valves are much beefier. They even offer to make the loud side louder but I opted for oem for the sake of my neighbours first thing in the morning. I'll happily send some photos or anything if you want it