hi bob
you can put on any 9-bolt or 9-1/2- bolt head from 1963 to 1973. beginning in 1973 the T140 uses a ten bolt pattern and you can make it work but you will have to oval one bolt hole in the head. i dont know whether the later parallel-port heads will fit your cylinders.
any difficulty will be with the pushrod tubes and seals, as the way they fit on the top and bottom changed in 69 and 71. the 71-72 system you have with the wedding band is about as good as you will get and can be retrofitted back to 69 without changing the tappet guide blocks, iirc. i think you can use the pre-69 heads if you just change out the guide blocks and get the appropriate push rod tubes.
put up some pitchers