1966 disc brake line size ?

[fleetman]

i have new cpp mc/pv - for the disc brake upgrade to my c10.
my proportioning valve has 9/16- 18 thread rear drum outlet for 1/4" tube.
the disc front outlets (2) are 3/8-24 thread for 3/16" tube.
i would like to use only one of the front outlets and 'T' off of it at the frame then branch to the rubber hose at each disc.
my question is do i use 3/16 tube for the whole length of the front ?
what is the best approach ? should i use 1/4 tube off of the 3/16 outlet ?
appreciate your comments.
paul