Well, my 97 F350 460 auto 4x4 has been under construction for quite awhile (5 years). I finally got it road worthy last weekend. I was pretty skeptical about passing the emissions test. I have shorty headers into a hollowed out catalytic converter into a flow master then dual 2.5" pipes. I gave it a solid tune up last weekend, plugs, wires, distributor cap, rotor button, & an oil change. I am happy to say it passed inspection on the first try. So IT CAN BE DONE! So many told me it couldn't and really I wasn't confident it would. Im pretty fired up to put this bad bitch back to work.