Originally Posted by brian12c
on a gen 1 sbc head what is the hole for that is on the exhaust side in between the far left and middle exhaust port? thanks BF
Temperature sender in the driver's side head.
The built-in water pump bypass is on the passenger side, so the driver's side head tends to run hotter.
Also the stock SBC water pump tends to flow more on one side than the other in varying conditions.
This picture shows the bypass plugged with an allen head plug for racing purposes only. Don't do this on any street car without other provisions for bypass.