I know one recall was for an oil leak that allowed oil to drip onto the front manifold and possibly causing a fire. I believe GM's fix was to install an updated version of the spark plug wire channel that you see just below the valve cover in front. My version is to replace the valve cover gaskets and grommets.

The only other one that comes to mind was a fuel leak issue, but not sure what years/models that covered. Call up a GM dealership and ask what may be available.