I couldn't find an exact breakdown of the code you have posted, but I did find a "TA" code that was used for the '65 230 and the '66-'68 250 used in 2wd C10 trucks with manual transmission. It seems that your code is missing one character, as it should have letter for the plant code (F is usually Flint) then a Month/Day code, and lastly, the application code. You might check for a casting date somewhere on the block or head. I can't really give you an exact location on that generation of Chevrolet 6, as my knowledge is more with the earlier 216/235/261, but you might look somewhere near the starter.
