[Nathaniel1234]

I have 1962 421 SD In a 55 Chieftain and am having some Cooling issues. I am running Hilborn fuel injection. Had some drive ability issues that seemed like it might have been vapor lock. Installed a water temp gauge and saw was pushing 210 degrees and counting. Yes, the issues of erratic rpms not relating to the amount of throttle returned once I saw temp climb. I felt the radiator and it was not even hot! Upper radiator hose was not even hot. I replaced the thermostat with a new 180 degree unit And new 13 lb radiator cap- did not help. Drained coolant from radiator ( it is the original 1955 Chieftain type) and ran a hose to top and watched water flow freely out the now open bottom of radiator... Seemed to flow through fine. The radiator externally appears good and even seems to have been recored at some point. Threw the thermostat in a pot of boiling water with a thermometer and it opened at 180. There is a hose going to heater core with a return. Yanked the water pump and shaft turned and stamped steel impeller blades are intact. I should mention that with the Hilborn injection there is some custom pipe work with a later style thermostat housing. What do you guys think the issue might be? Think it could help to eliminate coolant to heater core box? This is a hot rod kind of car and I am not concerned about functional cabin heat. Any other thoughts? Glad to take radiator to radiator shop to check/clean/pressure test...