To my knowledge, these are the original gaskets Boston bob put in on the
overhaul 40k+ miles ago.  I had a leak on the passenger side cover and
popped the bail and the gasket was split in 4 places!  Pulled the other
side and although it wasn't leaking, it had 3 cracks in it.  If we don't
set valves anymore, how often should we change these little jewels?

thanks

DM&FS