Well..... getting back to tire rotation.....

[Kazoo]

New stems or use the old?

[shimmy]

over 3 years... replace

[shimmy]

Are you rotating the tires front to back or criss crossing them?
I like to go front to back only, the steel belts are used to the one direction
If you do the X pattern, yes then change the valve stems, cause the stems are used to the same direction all the time , so if you change the direction of the valve stems they might get dizzy...