That is very possible.I am not sure what year they switch to more "readable" DOT/date codes.I know the early ones (60's to early 70's) had a more scrambled code.Dan P is the onboard expert on decoding those.But even with todays tires the last 4 number,or if it is pre 2000,the last 3 numbers,the first 2 are the week and the last 1 or 2 are the year