1969 350 Water Pump Issues

[JRBECK64]

I recently took my water pump off because the Aftermarket Chrome Timing Chain Cover was leaking oil pretty bad. When I took off the Water Pump I noticed that a lot of Antifreeze was coming out the bottom hole on the Drivers side bolt hole that holds the water pump to the front of the engine. This is telling me that the bolt hole is open to the water jacket in the engine. My question is, is that supposed to be like that or do I have a problem? The thing of it is, this engine wasn't leaking any fluid from that before the engine went in for rebuild. I plan on putting in a 1/4 inch allen head plug with some sealant on it to stop the leak and when I put the bolt back in it I am going to put some Sealant on it as well to keep it from dripping. Leaks Drive me Crazy. Thanks in advance for any help you can give with this.

JRBECK64