I bought a set of stock 1970--SS Wheels ( 7 X 14" ) from wheel vintiques. Some things I did not like. The wheels were powder coated the correct ARGENT Silver on Both the front and back. ( the back should be DOVE GRAY ). The front color that should be the bluish color to go with the Argent, Was NOT the blue type ( blue/gray -Charcoal) color, They were painted BLACK.
A friend of mine from MD.,, told me to scrape the black color on the front with my thumb nail, GEE, Guess what? My thumb nail removed the BLACK paint??? from the VERY SMOOTH powdered coated surface.
I would guess when you paint over a powdered coated surface, You " MAY " have to Prep, the surface and NOT just squirt some black paint from walmart on them. And, YES, I used my thumb on all four wheels.
Needless to say the wheels went back to Calif. Then I restored a set of O.E.M.- 70 SS wheels from my stash. When I buy a set of BRAND NEW-69-70-SS wheels that are EXPENSIVE,,, I sure as He!! do not want to spend time & money to make them correct.
Never want to go through that again!...............