brake line size, mastercyl for disc brake 14bolt

[kensdodge1]

on my dodge im runnin the the stock 3/16s brake line to the 14 bolt rear should i step up to 1/4 " line in the rear when i do the disc brakes or shouldnt it matter . should i step up the bore size on the master cyl. as well im still runnin a 1/2 ton dodge master cyl not sure on the size think its 1" .