Overheating issue??

[ABX131]

After my maiden voyage in my 63' to test it with brakes, I noticed the truck ran hot, really hot to where it spit coolant out the overflow. It also seperated the brazing on the radiator support (it is using a 57' Chevy radiator with the side mounting brackets). I changed out the thermostat and no difference. We then tore apart and flushed everything looking for any clogged areas. We had solid flow with a garden hose through every port including the heater core. I am confused as to where the issue is....any ideas??

[rideblue00]

What pressure cap are you running? Seems like pressure buildup was a problem. But why so hot? : Maybe timing off a little? Driving too slow?(not enough airflow)Cooling issues arent easy to nail down.

[Captainfab]

What was the condition of the radiator? Is it a 2 row or 3 row core? Are the cooling fins nice and straight, or are most of them bent over? What fan are you running? Do you have a shroud?

[ABX131]

Radiator looked ok except for the side mount bracket seperating. Some fins were slightly bent. No shroud. It has an external tranny cooler attached to the front of it.

[Rooster's 67]

So what kind of fan? elec or mechanical?
How many core is the rad?
what temp thermostat are you running?
is the thermostat in upside down?
what pressure is the cap?

[ABX131]

Cap is a 7 lbs stant w/flip up refief lever, thermostat is 180 deg installed properly, not sure of core rows.. it is an old Harrison radiator about 3" thick. Removed it and put the garden hose in the top while covering the bottom and filled it full then let it drain, had good flow coming out. same with heater core. Removed all H2O lines and hoses and flushed with the hose as well..

[Rich 5150 69]

after going thru your old posts your running a 350/350, a `57 chevy pu radiator will not cool what your runing, also your gearing I`m assuming is original which would in the 373 /411 range, your need to change radiators 3 row minimum, four row better, you`ll need a shroud for it, 5 blade clutch fan or 6 blade fixed fan, run a 192 thermostat, that will give the coolant more radiator time to cool down, check timming, if your on a real tight budget, search the wrecking yards for a 1970 to 1980 dodge diplomat, aspen, dart, powered by the 360 engine, most all will have the rad you will need with the ports on the top left and bottom right, with the rad mounts for the rad support on both sides. Run antifreeze......

[ABX131]

Thank you for the very detailed response. I will follow these instructions as they seem to be very specific and should be a big help. Thank you.

[Rich 5150 69]

Also suggest 12 lb cap with overflow tank, and your welcome.

[ABX131]

Rich 5150 69, thanks again..I found a guy parting out a 68' Dodge van/RV with a HD radiator and shroud. I cross referenced the year and model to a couple of sights which had pictures and dimensions and it looks like it will work. I am picking it up on Saturday for $50 and am also getting the overflow tank. I am also going to replace all the hoses and replace the H2O pump while everything is torn apart.