I developed a RMS leak. While I'm in there checking it out, I noticed the crank to flywheel seal was buna-n (or black any way), The gasket kit I have contains a silvery colored one. What gives? I would guess this is a rather high temp application.
I really don't want to fix this again. Any comments?

Don't know, but flywheel O-rings have a graphite coating that sort of has a silver sheen.
Ask on the bird board. Ask Charles at LN.