Leaky 400 RB... Any suggestions???

I doubt I warped the block, but I do worry about the heads...

I have not tried to retorque the cylinder head bolts, but I probably should pull the valve cover along with the manifold. I did try tightening the exhaust manifold bolts and they did tighten up a little bit, indicating that they were somehow loose... Sealant vaporized when it overheated? Still not quite sure. I'm very hesitant to pull anything apart as the engine was just rebuilt about 6 years (3,000 miles) ago.

When you say "if the bolt threads are leaking, they would probably be seeping oil", which bolts are you referring to and where would the oil be coming from?

Thanks a lot for your response. Much appreciated for sure.

-Mike