Tom, Not sure what your wheels look like, but, on my '12 DRW RAM Laramie I have Alcoa Aluminum wheels with small holes. The outer stem points inward and the factory mounted the DRW wheels with the stems facing each other.
I removed the wheels and reinstalled so the stems are 180 from each other.
I went to a large truck tire shop. There is a metal cap that looks like a regular valve stem cap, except you air thru it. I installed 6 of these. (my inner dual had a 2" plastic extension that I removed) (the cap is basically a 1/2" extension made of metal. Used on 18 wheel trucks)
Caps look like this
http://www.alcoa.com/alcoawheels/nor..._valve_cap.asp
Next, buy a tire gauge with the head that is straight, not angled like most. I can check and air now all 6 with out removing any caps. I also bought the air chuck that is straight. You can find both at truck stops and at parts stores that deal with truck stuff.
Looks like this
http://www.amazon.com/Milton-S986-Se...pressure+gauge
Hope this helps. Jim
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2012 Ram Laramie 3500 DRW 4x4 3.73 Tow Max Pkg B&W Companion 60 gal RDS aux fuel tank. 2014 Montana 3150RL, 2 A/C's, Leather, 6 Point Jacks, Splendede WD2100XC, Mor/ryde X-Factor, Duravis 250 tires with TST 507RV monitors. 2 x Honda EU2000's