I have a 88 cadi Deville v8. Have coolant in the oil but I'm not sure its the heads. I read somewhere that it could be the intake gasket but didn't really think it would be untill I was flushing the system out and noticed that it's a large leak that occurs when the radiator fluid level is at the very top. I was able to find this because I drained the oil and left the plug out while I filled the radiator. It is a large stream when it reaches full. Does this give anyone an Idea about where the bad gasket is?

Thanks in advance

 

Intake gasket is likely, however until intake is removed and old gasket is examined there is no way to tell. Intake gaskets fail more often than head gaskets. Head gasket leakage will cause run-rough and heavy white smoke. Checking spark plugs for signs of coolant can also be helpful.