@ Sir_loin
Yeah, pulling the head is a short job. at one point we had a problem with the air bubbles getting into the cooling system. All fine for a long time (months), then for no apparent reason it would give a giant burp and spew water/anti-freeze everywhere. Each of those times the fire ring on the head gasket had broken/burned through. Head gaskets from different sources and the problem still happened. Took the head to a machine shop to be resurfaced.........the old guy there re-sleeved my Dursley, and knew old engines. "does not need resurfacing" said he and told me to try again. I always have used a torque wrench, and had earlier found out about the silicone treatment, but still had the blown head gasket problem now and then.....same as before. Also the cylinder liner height was within spec, top of cylinder flat and square. Could not locate the problem then and never did......but no problem since and it has been at least 600 hours. Maybe a batch of not the best head gaskets, even though from different suppliers.
If you do pull the head, you might remove the hold down studs from the block and re-install them with a bit of loctite. This will make a seal at the lower threads so any coolant leakage cannot migrate down into the crankcase and then contaminate the oil. Won't take long and you don't have to remove the cylinder barrel. Just block up the barrel while applying the loctite......a couple of of clean 2X4 blocks work fine.
Yes, not so much fun in the cold........but it does get you to work faster! (I'm in Canada)
Oh Yes......almost forgot to welcome you to the forum. Glad you are here.
Cheers
Hugh