What type of flare for Corvette brakes

[vstol]

I am plumbing my project for C4/5 corvette brakes and was using the standard fittings and double flare. I was talking to a builder and he said you need to use a metric bubble flare to attach your line to the caliber. Is there an adapter or someone who make a hose that can go from standard to metric to fit the caliber? Thanks Kevin