quick question - what master cyl do i need?

[neverwinter]

hey all

my brother in law is coming over this weekend to help with the disk swap on my 63. i have the entire setup from a 79 ill be swapping to. simple question - what master cyl do i need? 1 inch bore or 1 1/4 in bore (stock for the 63 was a 1 in bore). these are manual brakes not boosted or ower. disks in front / drums in back. according to autozone, rockauto, etc there masters from a 72 are diff from a 73 and up. but i am not sure if i need to match the master to the 63 since that is what its going in (stock pedals etc) but obv need the dual master for the front/rear brakes.

i THINK i need a 1 in bore dual master cylinder. tha seem right?