I have dug deeper into the mystery but the factory parts books only list 1 cam for all 340s but there is no mention of the brief 6 pak production run or any special parts.
The factory book may have been printed before the T/A AAR s were planned though.
I have a friend with a couple & they definatly have more cam than the 340 4bbl but have the cams been changed in the last 32 years
He has a number of special bullitins that cover the T/A AAR but none list the cam.
Still looking into it , my friend is curious now too