Karl , I checked Y.O. catalog , they say:
MASTER CYLINDERS :
1969 with manual and or power drums

and for rebuild kits ;
1967-69 with power front drum and 1968-69 w/ manual front disc brakes w/ 1 1/8" bore diameter...NG501
1969 w/ manual or power front drum brakes...NG497 hope this may help some...
Bjorn