Topic: Correct Tail Light Bezel

[bpmdu]

Was hoping someone could help me out here, did a search and couldn't really find what I was looking for.  I see two different part #'s claimed as the tail light bezel for a 1966.  C4ZB-13449-B and C5ZZ-13489-A; I'm assuming the C4ZB part # is the factory one and the C5ZZ is the service part #?  From the pics I've seen both these parts look identical, which would make sense if one is a service part for the other - is there any real difference?  The C5ZZ appear to be going for more $ on eBay which is causing some of my confusion here.

[CharlesTurner]

C5ZZ was the number used to order a replacement part.  C4ZB on the tail light bezel is the engineering number. 

[jwc66k]

I see two different part #'s claimed as the tail light bezel for a 1966.  C4ZB-13449-B and C5ZZ-13489-A; I'm assuming the C4ZB part # is the factory one and the C5ZZ is the service part #? 

C4ZB-13449-B is most likely the part number actually on the bezel, generally referred to as the engineering number. C5ZZ-13489-A is the ordering number, stock number, billing number and reference number in the Ford Car Parts (aka MPC) books, the Ford service parts system. If you could follow the C5ZZ number thru the Ford service parts system, it would eventually have a reference that says to "Use C4ZB-13449-B". This dual number system actually consolidates several part numbers from different years and different Ford and Mercury models that are functionally interchangeable.
Remember, Ford was not building concourse grade cars.
Jim