I want to put new headers and a dual exaust on my 87 K-5. What types of headers should I use? can I use any GM ones and weld an O2 sensor on them? Anyway, there's a guy near me who can do custom exausts. He did my friend, Biggray71's dual exaust, except I want mine coming out under the rear bumper, not the rear wheel wells. What kinds of cats should I use? Will this new exaust screw up any computers or chips on the truck? Am I missing anything? Any advice from someone who has done this would be appreciated.