Good one to have - 7037213 is for 327/275 hp , standard trans, A.I.R, also for 350/295 hp, standard trans, A.I.R. A more common version is probably the 7027213, same engine power combinations, S/T, W/O A.I.R.
2726 is Julian date for the 272nd day of '66, you are correct -
Regards,
Steve