Re: Which chip
there really isn't any more "off the shelf" type chips for these trucks... only option is purchasing used but it's been proven time and time again that each truck and combo requires more tuning then what any generic off the shelf chip could provide.
so basically the only answer you'll get is to tune it yourself.. purchase an ostrich emulator, g1 adapter from
www.moates.net and download tunerpro to a laptop for free and begin tuning or take it a set further and wire a wbo2 up to your ecm and start using code59 which can be had at
www.code59.org
oh and the other option would be to go with a stand alone type engine management like Bigstuff 3, FAST etc which allows any decent tuner to tune your truck but it's costly route.