Water in the exhaust! Rrrrr

I had my 273 rebuilt about 5 years ago. I had tons of issues with the rebuild once I put it back in my car. They builder sleeved 6 of the 8 cylinders. It seemed like he did a good job so I didn't double check it when I got it back. I just stuck it in. First it blew oil all over the ground the first time I tried to crank it. (Missing galley plug on the passenger side. Pulled motor, installed plug. made sure driver side plug was in place and put motor back in. This time I used a primer rod and a drill to prime the engine this. NO PRESSURE!! The plug inside by the distributor was missing. Pulled motor again installed plug, put motor back. It sat for the better part of 4 years while I drove a 07 Dodge Charger that almost made me go broke. I got rid of it a month ago and started driving the Wagon again. It seems to run fine but I'm going through a gallon of coolant a week. No water in the oil or oil in the water. It must be the head gasket. The plugs all look fine. I guess I have to pull the top end apart and replace both head gaskets. That's all I can think of.

Any ideas.