Kind of a dumb question. I am installing an a/c unit in my Model A street rod. I am going to cut the holes in the firewall for the hoses. I will measure the hoses and the install the fittings no problem. With the fittings on the hoses, how do I now get them back thru the grommets. I guess I could cut the grommet and slip them on after the fittings are on but what if I decide to use the metal billet "grommets" to go thru the firewall? Any suggestions?