67 GT500 Black air cleaners

[acman63]

has anyone researched the approximate times/serial numbers  when they went from the bare aluminum to the black versions.  Also  ive got air cleaners in to restore  and im used to seeing the version where they are machined on the outside edge.  I just got one in today that is not like that and it looks original to me  pics are of 67 date photo in car and one  I took today

[Bob Gaines]

has anyone researched the approximate times/serial numbers  when they went from the bare aluminum to the black versions.  Also  ive got air cleaners in to restore  and im used to seeing the version where they are machined on the outside edge.  I just got one in today that is not like that and it looks original to me  pics are of 67 date photo in car and one  I took today

Yes, the lower picture is the version used on 68 Shelby's. Early 68 Shelby's did not use a hole in the center and are usable on a 67 if you restore it or machining a original one on the sides so that it looks like a 67 version. The 68 one is the version you will find most prevalent on the used market. I have seen a car in the later 400's that had the black wrinkle so think it was sometime around there until more compelling evidence suggest otherwise. This info is still evolving.

[2112]

Is it known why they went to black air cleaner assemblies but did not switch to making the valve covers black as well?

[Bob Gaines]

Is it known why they went to black air cleaner assemblies but did not switch to making the valve covers black as well?

I have only heard what can be considered as speculation although logical . No concrete documentation that I am aware of . When the lids were changed from the sand cast to the diecast to make lower cost and larger amounts of units needed compared to previously it was found that the large flat empty surface of the die cast lids came out with defects in them. The surface typically had some thing that would be considered a non smooth surface flaw  . Some more then others. The black wrinkle paint effectively disguised these defects. The sand cast valve covers didn't need it. It is interesting to note that in 1968 when the valve covers changed from sand cast to diecast the same evolution of finish occurred.  FYI the 65/early 66 sand cast open letter valve covers were bare aluminum and the later die cast closed letter valve cover have the wrinkle finish. Another example is the 67 gauge pod. The wrinkle paint does a convincing job of making the texture of the gauge pods and the smooth surface of the sheet metal center panel match each other .     

[2112]

Interesting,

By the 1970 model years, the dies cast parts were very good pieces.