Just recently purchased this car and found that it has lot of rust in the radiator. How I found out, is the heater core exploded and leaked out. Changed it out with new one obviously and then refilled the radiator. After several long minutes, noticed the coolant turned brown. Drained it, little came out of radiator when I did this. Wasn't really thinking about how little came out at the time. I filled it up again using a spill free funnel. After several minutes of running the engine, I gave it some higher RPM's at 1500 to 2000 in order to get the coolant to circulate and thermostat to open up. I released the RPM's back down to around 750 and noticed the large amount of bubbling came up and out of the spill free funnel. Think maybe its only a clogged radiator?

 

did you change the thermostat? did you flush the engine before installing new radiator? better late then never. i would take the radiator out and flush it using garden hose. unhook heater core hoses and flush using garden hose, when doing this do not use much pressure, core normally has little pressure on it (10lbs) so 50 lbs of water pressure can do some damage.