Please post pix of orig 1966 gt360 carb.....

there is no one date code that would be correct. any 1966 date code before the sale of your car from Shelby to the dealer would be OK. It will be be the 3rd line of numbers on the air horn. There will only be 3 digits. The first digit will indicate the year, so it must be a 6. The very early '66's could have a 5. The next two digits indicate the month and the week. For example, my carb came off of a '67 GT-350 and is date coded 713 (1967/January/3rd week).

Z. Ray

 

6S923 has the original carb dated 581, i.e. first week of
August 1965.
Texas Swede

 

When I had the carb rebiult & replated by Pony Carbs, they told me my October 1966 built 67 Gt 350 had a carb date of March 1966. I figured Shelby probably bought these carbs by the pallet so, no, I had them rebuild what I sent them.