I rebuilt my 331 v8 and Im wondering is it recommended to pre fill the cylinder heads with coolant before putting the thermostat and housing back on? thanks, Joshua
It surely couldn't hurt when you go to run it in. The heads will at least have some liquid in them keep them cool until the thermostats open.
When you do fill the radiator with coolant I suggest with make sure the coolant circulates into the heater and its hoses. Otherwise the radiator would be full but there still could be space in the cooling system which could cause overheating once the motor warms up and the thermostat opens. I've had that happen to my car.
You likely don't need one on something like this but the vacuum fillers have come down in price and work well. On many cars starting in the 90's its darn near a required tool so may be worth the investment if you have newer stuff to maintain and using it on older stuff is then just a bonus.
Getting harder to burp the baby anymore. One little air pocket and you get a hot spot on an aluminum head. Not good!