2008 silverado brake line size

[StarshipCoder2000]

trying to sort out the brake line size for my 2008 silverado. looks like it's a 1/4 line but the flare nuts aren't 1/2-20 like i expected. everything i find online only covers pre-2007 models. the old line rusted out and split so gotta replace it. anyone know the right size for this?

 

[JohnConstantine]

many people say that gm uses oversized nuts so theres your answer to that but since its the brakes i say take ti to a mechanic, just in case