JEEBUS at this point I recommend changing your strategy, cuz that engine has an internal problem that has been touched on by others with too much crud binding up the mechanism. I have rebuilt 2 flatheads without removing the engines, including replacing valve guides. One truck I managed to do this without removing the dog house, just the hood and inner fenders. As it was pointed out to me by old timer mechanics who have been long gone, local service stations could rebuild engines without removal as most vehicles built into the early 60s could be worked on without a lift or engine hoist. These buggies had not been parked for decades, so all they typically needed were a ring job, valves ground and new guides, and a seal kit.
If ya cannot turn the ring gear, then surgery is required to determine what's binding before doing some damage. Pulling the head and valve covers for sure, even the oil pan needs to come out cuz if that crank is crusty, it ain't gonna matter what's soaking the piston rings loose.
One of those flatheads that I rebuilt, drove that thing for 15yrs and then it started having what I think was a partially spun bearing due to a worn crankshaft that needed attention. At the same time, I was flooded with work and chores and helping out the elderly neighbors with increasing mobility issues; 5yrs went by, I went to turn that ring gear on the engine that ran when parked, and it was a no-go...even sitting closed up with oil on every surface needed, it jammed up. So it's on the overhaul list again, hopefully it'll just need crankshaft service and oversized bearings to rectify its problem, as it ran well and never smoked or leaked.