Now I have a little more fuel for the fire.
In regards to the CARbureTER Made in USA casting compared to the CARTER casting on the 67 GT500 pumps, I have a 3909-S pump dated June 30, 1967. The CARTER name change for all other non fuel filter canister pumps on small blocks and big blocks occurred before March 1967. I have not done enough original 67 GT500 pumps to observe either a CARbureTER or CARTER casting prior to the June 30, 1967 one that I have in stock. All of the original 67 GT500 pumps that I have done so far were dated prior to the 1967 calendar year. I have observed standard 289 pumps with the CARTER casting by February 1967. So far the last CARbureTER casting for a Hipo 289 (GT350) is December 1, 1966. The major change for the 1968 model year was the inlet nipple size changing from 5/16" to 3/8".
Again I encourage constructive criticism here as I am always open to learning new things.
-Fred-