Howdy Back:
The question is what year is your block casting?
If the block casting is a C4, or '64, a DS II will not be an easy upgrade, because of the hole size and drive shaft differences Patrick stated.
If your '65 is a later casting, either C5 or C6, the later distributor should be a direct swap-in.
Check out your block casting #. Does this 170 have hydraulic lifters or solid?
Adios, David