Quarter Window Leading Edge Seals

These come in flocked (covered with a velvet like coating) and unflocked (bare rubber). I am not sure why the difference and there is no definitive info to be found.

E bodies - I do know, for example, 1970 E bodies used the flocked version of these quarter window seals and 71-74 E bodies used the bare, unflocked versions

62-70 B Bodies - I have heard complaints about tight fit and difficult installation of the flocked seals and the unflocked seals fit and installed perfect.