[walterjay]

Is there an easy way to tell if I have a cracked manifold?

 

[62pan]

If the engine will run, try bleeding some propane around the manifold from an unlit torch and if your rpms change, you should be able to pin point closer (crack or bad gasket ) once you know the area where you get a rpm change. just a thought.

 

[JohnW]

It is most likely at the rear of the manifold if you have a leak, that is where they errode most of the time. Use the propane trick or spray the manifold with something like WD40, the rpms will change when you find a leak on the intake side. I assume you are meaning the intake, since the exhaust side generally shows up.