unity spotlight bracket question

[GSPI]

Originally Posted by Va 5.0

221RH is what you need to put the spotlight on the driver's side pillar
221 will work on the pasengers side

From an old post:
The 221 brackets were made for various, '70s, GM cars. The 221RH bracket is for the passenger side of those cars. Later, it turned out that the same brackets would work on the Ford Fox Body cars, if you switched the brackets around.

Unity instructions state 221 and the 221RH for passenger side.