Alright - as an update - I went the twins route and couldn't be more pleased with the results. Honestly, if you don't have them or have never driven them, you cant really say not to do them because they make one hell of a difference. Just completed the kit this weekend with a slew of other changes (manifolds, up-pipes, tuning, lower temp T-stats) but the results are impressive so far. EGT's barely crest 1100 on max effort WOT (unloaded), cruise temps are about 650 (down by about 150-200 deg), MPG is up about 2.5MPG, boost readings are about 42PSI max effort WOT (probably some adjustment to do there and i found a crack in the stocker intercooler - next to upgrade). I'll be putting together a video for the truck and some of the install on Youtube over the next few weeks as well as showing before and after towing results. :thumb: Install took about 40hrs of direct time - including dropping bolts into the no-man's land of the engine bay.