He handles tunes via mail-order but obviously they won't be as good as those done on the dyno with your truck. The headers I mentioned were true duals which included hi-flow catalytic converters, with or without mufflers. With true duals mufflers aren't going to cause any restriction on a non-intercooled truck. The tune needs to be written for the modifications the truck has. You can get it before the exhaust, but you'd need to get another set of tunes done after you get the exhaust. All tunes need something to load them on the computer with. On 2004+ you have to use a tuner. On 1996-2003 a tuner or a chip.