Brake booster Vaccuum hard line diameter

[cis6409]

Hi,
Does anyone know what thickness (outside diameter) of the frame hardline that goes from engine to the brake servo part number #100416 is?
Is it imperial or metric size?
I need to make a new one for mine, I thought it was the same as the fuel hard lines 5/16", but it looks bigger..?

Many thanks
Shane

[Ethan Rode]

Should be close to 3/8". The hose is 11/32"

[cis6409]

Thanks Ethan, I'll go for 3/8" then

Cheers