How close is too close? I'm not aware of any spec that identifies a minimum distance from fluid carrying lines or components. I thing my master cylinder under the floor may be too close to my header pipe and my fuel line too close to the header pipe on the other side but I have not noticed any operating problems. On a hot day cuisin the car show at idle speed everything is workin' good. I have maybe two inches clearance. I would agree with what Lynn said above if you feel you need to do something.