Mercedes Sprinter dually tire pressure

Well, the deed that started this whole topic string is done folks.....I had the six steel valve stems I got from Bill installed 2 days ago at my local small town tire shop. All considering it went fairly well...with me hovering nearby to observe and kibitz from time to time. I did all six tires and surprisingly the front gave the most trouble because the ones provided with the kit were really too short to adequately clear the hub cap...and they also needed some bending to keep from touching the wheel cover. They are still closer to the wheel cover than I would have liked, but hopefully it won't be a problem? Luckily I had also ordered six of the little 3/4" flow thru caps and that just made the new stems long enough to easily get a gauge on them. The rear dual wheel installations actually went in the best with a little bit of bending necessary which the shop tried when I showed them Bill's installation sheet. We'll see how they perform on the road and with a little time on them....I'm keeping my fingers crossed! Thanks to all who posted and gave me the benefit of your experience! Snoop

PS: I do have a question about tire pressure? The tire shop recommended 80PSI, and the door jamb tag says 61PSI on all six tires. I probably carry only about 4 or 5 hundred pounds of weight in the RV which includes myself and am inclined to inflate my tires to the 61 PSI figure. Any suggestions?