I have a fuel economy guage that I would like to install in my 88 240. I know that there is a vaccume line that runs of the one of the intake manifold. The problem is that I have to get this hose inside the car. I really don't want to drill a hole in the fire fall to get it inside. Does anyone know of a way I could get it in the car with out going to such drastic measures? I don't want to drill a hole for two reasons. I don't like drilling holes in cars. Also, If I were to find an outside temp guage, I might take this guage out. There is is probably no vaccume lines under the dash that woud give me the correct readings is there?

Thank you very much and Happy bricking.