brake line size when converting from drums to disk?

[lime4x4]

Currently boat trailer has 12" 6 lug drums with a hydrulic actuator. Converting over to 12" kodiak disk setup with a electric over hydrulic brake rite II sd unit. The current brake lines on the trailer are 2 years old and where made with 1/4" brake tubing. I see the actuator and caliper uses 3/16" brake lines. I also purchased 4 new 3/16" brake hoses with the calipers. Do i keep the existing brake lines and just use adapters where needed or should i just run all new 3/16" brake lines and keep the adapters to a minium?

 

[2000SEARAY280SS]

I did the same upgrade to the Kodiak disk brakes and after adding the disk brake master cylinder and the reverse cutout there was not much left of the original break lines and I replaced them all. The original lines had dried out once from the previous user and had some rust build up.