Tires: Tire pressure, surface irregularities, gmc sierra

Question
Hi...I recently purchased new Michelin 265 75R16E tires for my 2003 GMC Sierra 2500 crew cab diesel truck and would like to know the proper air pressure for these tires for my truck. I bought this truck used and it also had 265 75R16D tires on it, although the door placard as LT245 75R16E on it.  The place where I purchased the tires put the pressure at 66PSI, and that is where I have kept it, but I am now seeing wear signs and the inside and outsides of all four tires.  I really need to know what pressure to keep these tires at.  Thank you,

Answer
Robert,

Included on the door placard should have been the pressure for the LT245/75R16's.  The size / pressure combination will determine the load carrying capacity of the tires and matching that to the new tires (factored by the size) will determine what pressure is appropriate.  

I've checked my books and there are quite a few different versions of GMC 2500's - and they have different pressures - so I will need to know what YOUR vehicle says.

And just to make sure:  My books also say that the stock wheels are 6 1/2" wide and an LT265/75R16 requires a minimum of a 7" rim.  So if you have the stock wheels, the vehicle may be sensitive to road surface irregularities, particularly grooves and ruts in the pavement.