Cooling
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,112
From: Crossville TN
If the stock rad has been de-limed and cleaned, is not damaged, the radiator seals are good and in place, the stock thermostatic fan is there and functioning properly, you have a hi-flow 180*F thermostat, and the pump is good, your ignition timing is appropriate, and the vacuum advance can on the distributor is connected to 'manifold' vacuum (instead of timed/ported vacuum) you shouldn't have overheating problems.
Or, as mentioned above, install a 3 or 4-core aluminum radiator and have no problems.
Or, as mentioned above, install a 3 or 4-core aluminum radiator and have no problems.
Drifting
Joined: Jul 2015
Posts: 1,765
Likes: 253
From: Catlett VA
radiator
I agree with resdoggie. The PO installed an aluminum radiator in my 68 convert with NOM 454 engine, which runs even hotter than your 427. When I got the car it had both the belt-driven stock fan and a pusher electric fan, which did not have a thermostat and ran all the time. I finally removed the belt-driven fan and the stock fan shroud. I also installed a relay that turns the electric fan on based on the coolant temperature. The electric fan, aluminum radiator and the "shroud" for the electric fan keep the car running cool in traffic. If you decide to get the aluminum radiator, measure the available space and get the biggest one that will fit, preferably a three row core one. Also invest in a thermostatically controlled relay to turn the electric fan on and off based on the coolant temperature.
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Tech Contributor
Joined: Jun 2004
Posts: 20,779
Likes: 957
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
If the stock rad has been de-limed and cleaned, is not damaged, the radiator seals are good and in place, the stock thermostatic fan is there and functioning properly, you have a hi-flow 180*F thermostat, and the pump is good, your ignition timing is appropriate, and the vacuum advance can on the distributor is connected to 'manifold' vacuum (instead of timed/ported vacuum) you shouldn't have overheating problems.
Or, as mentioned above, install a 3 or 4-core aluminum radiator and have no problems.
Or, as mentioned above, install a 3 or 4-core aluminum radiator and have no problems.
I especially agree on the appropriate timing curve rather than the stock timing curve.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,112
From: Crossville TN
Stock GM set-ups (especially from '71-later) were intended to run with retarded timing for 'emissions' reasons. That caused them to run 'hot'...especially at idle and at slow speeds.
Last edited by 7T1vette; May 6, 2018 at 09:04 PM.