Removing 340 heads

So you were thinking head gaskets for an oil leak? Or did I miss something?

If you have a leak, I would start with the valve cover gaskets.

This car sat for 25 years on jack stands. I've been working on the brakes knowing I have some leakage from the valve covers but after running the engine for the last few weeks severe leaks developed that required some level of disassembly. I couldn't see well enough around the back of the engine to determine if I had a head gasket problem so I was prepared to remove the heads.

Don't want to if I don't have to at this time. Know what I mean?