440 engine making a noise that sounds like an exhaust leak, but no leak is found

[Jayarr]

Engine, a motor doesn't have exhaust leaks.

Real car guys use the term.

 

[furious70]

What does that plug look like compared to the others?

 

[DC118us]

I’m going to level set. Reassemble everything and do a compression check. Then pull the exhaust manifold if compression is ok. Replace oil and go from there