Need some help, I want to put a new fuel filter in 1980 deville, 368, it's right in the carb body, and involves two wrenchs to remove old one. one of the wrenches is a 15/16" , the other wrench ( to remove fuel line) is somewhere around a 9/16, 1/2, or ??. one is too small and the other is sloppy and might round soft nut. does anyone know actual size?. tkanks.