rear rubber bake line

[65 starfire]

hi,was wondering if anyone knew why when i order a rear line ,they send me a line with a 1/8 inside dia. instead of 3/16 , like the rest of my lines,is the rear suppose to be smaller for some reason ,thanks for any input, must not of been the right tee on the rear either, because out of three different lines , only one almost worked ,that was for a 66 starfire,tee bolted right to the pumkin, on mine it shows in the book to be bolted to a bracket , ???? thanks will.