I know that there were some differences in the assembly procedure / application that varied plant to plant. I know that the under coating was applied a certain way with 1" tape over the holes and other areas masked off. Was there any differences between the two plants with b bodies such as black painted leaf springs vs. natural heat treated ones?

I am in the early stages of starting to freshen up a 69 GTX convertible and would like to get some knowledge on the St. Louis plant before I really dive into this resto.

Thanks,

Brian