My motorhome came equipped with metal valve stems that bend at a right angle, and for the inner duals, point straight out. The only problem is that they are too far in from the outer dual wheel hole for my tire gauge to reach. I purchased solid metal valve extenders. They come in lengths in 1/2" increments. I have been using them now for over 3 years and 67000 miles, with NO problems at all. I will never go with anything else. You can get the extenders at most truck tire dealers, or truck parts suppliers.
2000 American Tradition
1999 Saturn SL2 toad