[Jack21]

Ditto the above. Bad advice from an engine builder.

These street motors need to be at proper operating temperature to work properly. Run a 180 degree low restriction thermostat (like Robertshaw) year round.

The higher the pressure relief on the rad cap, the higher the coolant temp can go before boiling. But, the higher the stress loads (and life expectancy) on hoses and hose connections. I went with a 7 pound Stant cap, and so far (2 years & 12,000 miles) so good.

That being said, Cobras have notorious reputations for overheating so install the best cooling system components you can get. Griffin aluminum radiator. Pricey, but it does work well. Healthy electric fan properly mounted to its own bracket, with manual override. High flow water pump like the Edelbrock or comparible. If using March pulleys, use the Street Rod ratio, not the high performance ratio because it flows more coolant.

You'll thank yourself when you're stuck in Summer traffic and your Snake keeps its cool.