Anyone know what these numbers mean? Found them on my Shelby

[GT500J]

Thanks

[Bob Gaines]

Thanks

I assumed you outlined them so that they would show up better. I haven't seen markings in that exact place before but they were applied prior to paint to give instructions on how the car was to be completed typically. It is not a typical location like other places from what I have seen on paint stripped 67 Shelby's . I typically see instructions on the front side of the radiator support . In that case in reference to being a Shelby unit ,engine size,DSO to name a few. The writing is covered up when the engine compartment is painted. They will not be seen when done. I wish i could tell you what that particular writing means maybe someone else. 

[J_Speegle]

These marks IMHO were applied to the sheet metal for a different purpose than the ones applied to the radiator support on some Mustangs at various plants. I've got records of this pattern (we discussed it in the old site) on a couple of the inner fender panels at San Jose and Dearborn plant back to 64 1/2 production.

Given the rarity of the markings and that they were applied when the metal was bare it is my opinion that these markings were applied to a stack or pallet of panels for identification by either the stamping plant or for shipping purposes to the car assembly plant. So only one out of maybe 100 or more panels would have received these and in turn that is the reason we rarely find them.

Patterns are all pretty similar in number of lines and similar letters and numbers in that pattern

As for markings on a 67 Mustang (and in turn Shelby's) there were marks that were applied as reminders or short hand both above and below the black engine compartment and even the body paint.

If you could - would it be possible for you to PM this cars assembly date or a partial VIN so I can put it on the list?  Even that panel date would help place it in sequence to the others I have on file    Thanks