I had one just like this that was stuck. The real problem was the valves.I found out which ones were stuck by prying down on them between the rocker tip and the top of the valve stem. I tried spraying some lube on ,but not much luck. I was able to move the rocker out of the way and used a handheld propane torch on one valve that was easy to get to. I was careful not to over heat. Keep touching the valve spring and valve tip as a heat indicator, by heating,tapping,prying etc, I was able to get the feel for how it was going. Got several of them free, and was able to start the engine. I also like to overfill the crankcase with atf in order to flood the rear main seal. I think if the cylinders are rusty, the piston/cylinders will be damaged. This 216 had an 80's inspection sticker on it so it was resting a long time. I think the valve sticking issue may be the whole culprit.
