Aftermarket hose fitment

Swapping to disc on my 72 duster I got some cheapy O'Reilly hose for the interm.But the fitting does not have the flat on it like the original had,the tab on the front frame rail has the flat.Are you all just drilling out that flat on the tab so the aftermarket hoses slid in, or is there a specific hose I should get.I tried the 80 volare and 74 dart/duster hoses and they are all the same(no flat on the fitting/connection).