Does it have a full magazine or half mag? 20” barrel or 24”? If it’s a full magazine it’s a 336RC or Regular Carbine, 20” half mags were Sporting Carbines, and the 336A was the half mag 24” rifle. I’m not positive it I think that by the 70’s the only two options would have been the RC and the A and I don’t recall ever seeing one so stamped.
