Well sorta.
1) you want high pressure
valve stems for LR D (65 psi) or E (80 psi). They may be rubber but will generally have an elongated stem.
Could go into a long discussion of the differences in construction for different load ranges for a specific volume but won't.
2) My wheels have the description stamped in the side of the wheel, it is visible when the tire is mounted. The JJ refers to the rim bead configuration.