3/16 or 1/4 in brake line for all drum brakes?

[64stpside]

I getting ready to start replacing the brake lines and have seen conflicting reports/opinions and brake line size. As Ive stated in other threads about my brake system, someone put a disc/drum booster, mc and prop valve from a early 70s truck on it. I had 3 different size brake lines on this truck.

Do I:

1. Install all 1/4 in lines?
2. Install all 3/16 in lines?
3.Install 1/4 in lines back to the rubber hose, then go to 3/16?
This is what I think is correct as I want to do a front disc conversion at some point and I believe the front lines need to be 1/4 for a disc system, unless a all drum system need the same size lines through out....