Re: Whats the proper temp thermostat for a 69 350 SB?
If you're using Smokey's vent holes you should read what he has to say about engine operating temperature:
Running an engine at 180° will drop the overall horsepower by 2-3%. For max power the coolant should be at least 200°, and you should have at least 25 pounds of pressure in the system. Actually a racing engine like the smallblock Chevy will produce more horsepower as the operating temperature is increased, all the way to a maximum limit of about 220°.
Power Secrets - Pg. 121