I installed a chrome mechanical pump on my sbc 350. I used 3/8" brake line and ran it from the tank up to the pump. Then I used a braided stainless line and anm fittings to go to the carbs. I sprung a leak at the inlet side of the pump. So i backed it out and used some of the rtv in the white tube. the stuff is actually brown. Tightened it up and the the next day it leaked again. I am thinking that the fitting on the brake line going into the pump inlet is too short and may not be seating properly. Nothing else leaks any where.