I have been looking at exhaust for Big Red 2 since I got it. I have had the stacks on a 12 valve Dodge and have had single exit on an 03' Ford. I'm curious about dual exit on a 08' f250 and what it looks like. I don't know if 4 inch turbo back dual or 5 inch turbo back duals will look like. Also since it has twins (Twins Bazzel, twins!!!) my thought would be the 5 inch better cause of exhaling alot of air. I'm not wanting for alot stupid just blow it apart performance cause personally it pulls stock like my 6.0 did when I had the Bully Dog triple dog on it set on its highest setting so anymore will be LOTS of more fun. Course now I'm thinking about a programmer. God I think to much. But actually so far I'm still cheaper than my custom trike that got destroyed. I want a good programmer but would like shift on the fly. But if not one that doesnt take half a century to load and blow head gaskets and egr like crazy. Also must have good tranny tuning to. Also I know its proably stupid to ask but do you still need to put a pyro probe in on these newer trucks? If you can't tell I have been out for awhile for diesel performance (since 08') but so far everyone has been real cool which I say thank you.