Hey there i have been having some issues with the 390 i just built and installed in my 68 wagon. Its a 1966 390 600cfm edlebrock 4bbl with brand new everything and a 3 core core radiator with a 180 thermostat and duel electric fans. Hopefully someone can help me. It overheats while idling but cools to normal while ddiving. Also my heads where they meet the exhaust manifolds are turning white as if it was running super hot. Any thoughts.? I replaced the thermostat bled the system and nothing. Its driving me crazy. Dont think the head gaskets are on backwards.