The Stovebolt Site Forums The Shop Area Engine Shop 235ci Engine Overhaul

I'm overhauling a 1955 235 engine and I have a couple of questions / concerns:

1- after removal and cleaning the block head I've found a couple of markings / stamped letter on the surface that contacts the block. They are "C" and "E". These are located in surface located near the # 6 cylinder valves. Also a raised letter "A28." What could they mean?
2- i've checked the block head for straightness using a 4 foot aluminum level. It appears to be straight. Should I still have the head refaced? How many times can you reface these cylinder heads?
3- The flywheel looks like it has some surface cracks. We have a 216ci engine and its flywheel is good. Can we use the 216's flywheel ring gear and use it on the 235's flywheel?