When I was 17, i took the tired 351M out of my 79 F-250. The next morning after getting it out, i got impatient waiting on my friend to arrive so we could swap over the flywheel to the new motor. I was def young and stupid, so I figured I could hold the flywhhel up with one hand while I removed the last bolt. I had my hand directly at the bottom, and when the bolt came out, the flywheel droped staright down onto the shop floor smashing my pinky finger. It broken the bone right at my last joint and tore all the skin off the end of the finger. Pretty nasty to say the least. I was extra stupid in waiting to go to the ER antil after we got the motor hung in the truck. I simply wrapped it in a shop rag, and put duct tape over the rag to hold it in place. Dumb dumb dumb! The virtue of patience is learned slowly over time, and through painful experiences in my case.