Are 930 valve cover gaskets (the green ones with the grey sealant stripe)
incompatible with early valve covers ?
I've never in thirty years used anything but a bare gasket.
My own car is leaking after a valve adjustment like I've never seen before.
The grey gaskets that came off didn't leak.

We always used the gray gaskets on everything.
The green gaskets don't squish as much which is OK with 930 valve covers.

Were your early valve covers flat and not cracked?
They tend to distort and crack with use.

Jim

The valve covers do very well with a straight edge. No cracks or flaking.
What it think happened is I tightened the lowers un-evenly due to the
tight confines. It seems the thin green gaskets don't tolerate this.
I'm doing them over using grey gaskets, heat exchangers removed.
I'm hoping the improved access will allow more uniform clamping.
Never had a problem in the past with the HE's on w/grey gaskets.