Does anyone know the proper size inner tube for 165-15 tires. Auto parts guys seem pretty helpless about this. Amazon shows 2 sizes that maybe look right (1)G/Gr 15 TR13 and (2)700/750 R15/16 Also, anyone know the code for the type of valve stem. I found a tube in a parts store but it had a long valve stem , for trucks I guess. George Vernau