Front ones were yellow cad plated, rears were clear/silver cad. They are interchangeable LH and RH but I think fronts are different than rears. The fronts usually got covered with a bunch of sound deadener, so nice plating isn’t really necessary.
I just saw this reference to valance painting in another post about the Chrysler assembly line process. A very interesting read focused on SUPERBIRD production:
“…For color-coating, the valances are hung with short wires from the roof rails inside the passenger compartment, and painted there by...
That appears to be a 383 baseplate. The stamped hole in the raised round boss at the front is unique to 383s and usually indicates that a factory original part. Later NOS 383 bases dropped the stamped hole.
Here’s a reference to help confirm what base you have:
4-Barrel Shaker Bases
Engine...
I bought these two ago (maybe 20) from a couple guys vending at Carlisle. They did a bunch of air cleaner option key chains if memory serves. They also sold plastic plugs and covers in kits for engine storage and painting. I still have their kit for a 340. I can’t remember their names but they...
@dombee I have a nice set of rechromed originals for $250. PM me if interested. You may also want to look at AMD repros if OE isn’t a that important to you.
https://www.autometaldirect.com/rear-bumper-guards-70-72-challenger?