After getting my 216 fired back up, I realized I have a leaky exhaust manifold. When I bought the truck, the exhaust system was pretty much non-existant so these leaks went unnoticed. There are two leaks, the port in front of the carb has about a .018 gap and the one behind the carb is about .013. Two questions :

From everyone's experience, what is the likelihood that I am going to break off some bolts getting this off? I'm trying to decide whether to do this myself, I really don't want to get into drilling/tapping broken bolts.

Any chance that tightening things up would close these kinds of gaps. Are there any other short term fixes? I would really like to hold off doing this until I get some other things out of the way.