273 coolant drip right exhaust bolt hole

Hi Folks,

This is my first post on this site and I am new to mopar in general. I have mechanical experience, but not mopar.

So, here is my question. I am working on a 1965 Barracuda with a 273 and auto trans (not sure which trans). I removed the exhaust manifolds to replace the gaskets. Also had a coolant leak at the thermostat housing and after repairing that I pressured the cooling system up to check for leaks. I was surprised to a slight drip coming from the right rear exhaust bolt hole. I see there is a freeze plug at the back of the head right near the threaded hole telling me that coolant is not far away. So, how big of a problem do I have here with that coolant leak with the exhaust bolt removed.

Second question: Should any of the exhaust manifold mounting bolts be studs rather than bolts. The right front one on my engine is a stud and all others are bolts.

Thanks a lot for your experienced advice.

Rick