I had Doug thorleys on my Pickup with weber, bs elim kit and no cats but I still managed to blow out one of the tubes from heat fatigue. I did like the seat of pants feel but there were constant leaks even with the doug Thorleys. What I have run for the past 5 years with better results is a montero cast iron manifold with precat that I gutted with the aid of a long screwdriver. 2 1/4" pipes and a turbo muffler which actually exits in front of the rear axle on my flat bed away from harm. If you are set on headers, It wouldn't matter which you went with as long as you make two mods: 1) Professional ceramic coating not spray can, and 2) cut out the 3 bolt flange and weld in a ball flange joint with grade 8 bolts to attach it to the rest of an exhaust.