Dan,
I am a little confused...did you actually replace the gasket with a brand new one? Are you doing this with the tunnel installed?
The rules I live by now is whenever I do a gasket with RTV or just RTV alone.
1. Total cleanliness
2. just snug up fasteners until squeeze out
3. final Torque the next day or an hour, I forgot. It is after it sets up.
4. do not operate until it is all set up for 24 hours
Do you know the Torque spec and pattern to tighten these up to?
Is the cover straight forward, no surprises inside?
I will follow your lead and inspect the cover for flatness. Is this thing thin like an
oil pan or valve cover?
Dave