Help! Adding late model molding, need measurement.

[lt1wrangler]

My 1988 Suburban didn't come with any molding but Ive decided to add it to the new paint and was wondering if anyone had a measurement from the body line to the top of molding? It appears the chrome style molding rolls around right under the taillight but the black style ribbed molding is lower. Whats the difference?

Id really like to know what everyone thinks or has run across before. I already purchased the pre cut package from LMC.

Thanks in advance