For anyone planning to replace the oil thermostat gasket, don't do what I did. I removed two of the three bolts holding the thermostat to the block (the top bolt and the lower/front bolt). Then I removed the T45 bolt holding the oil lines to the thermostat. When I tried to pull the lines out of the thermostat, the thermostat cracked around the third bolt (lower/rear). So if you plan to remove the lines from the thermostat, do it while all 3 bolts are still holding the thermostat to the block. That aluminum casting around the lower/rear bolt is pretty fragile apparently. So now I am buying a good, used thermostat. As if the job wasn't a pain enough, lol.
James