traveler,
The best place to start looking for answers to the questions you asked is the content side of TDP... Click on the Duramax 6600 Diesel Page link at the top of the screen. There are a number of articles that will address most of your questions. The search feature will turn up more info and I'm sure other members will chime in as well.
Bill
03 2500HD D/A CC/SB/4WD,OilGuard, MegaFilter,LiftPump/PreFilter, Bilsteins,RetraxRollTop,J&J Boards,Coolant Filter,AlliDeepPan,FastIdle,AllHeadLightsOn,
98 K3500 6.5,SOLD