A few years ago I had a 1954 261 that had sat for 43 years, and it would not budge, even with Kroil in the cylinders for two weeks. I needed to remove the crankshaft gear, and then the crank and pistons would move. The clutch, flywheel, and bellhousing could now be removed. It seems that the camshaft had "frozen" in its bearings. The crankshaft would now rotate fairly easily and the cam broke loose after I attached a 36" bar to the cam. After cleaning up the engine and putting it back together it runs great. Thus, there are many reasons for the engine being "stuck": pistons, rings, rod bearings, main bearings, lifters, cam bearings, rocker shafts, etc. Always pull the rocker arm shafts.
Hoyt
