Sucks about the heads, but I agree with you! I cant leave anything stock. My truck, my bronco, my jetta, all have aftermarket exhaust, CAI's, tires, wheels, etc. Its what gearheads were born to do. I even borrowed my moms Envoy Denali and it came home with a flowmaster catback setup
My buddy works at Ford, he is a diesel mechanic and I hear nothing but bad about the 6.0 motor. Maybe it isnt as strong/reliable as the older or newer ones? Whatever the case I hope it is covered by the warranty.