I always bag the engine unless it's on diplay for viewing purposes in which case I just cover the top. The crankcase is full -not overfull and nothing is left loose. Once every couple of weeks just give it a few spins. If your clearances are correct and everything has been lubed and primed you have no worries. I would suggest pulling the distributor and drill priming again prior to installation or use an oil gallery primer. For flat tappet cams make sure you run a can of EOS in the crankcase as well and in the next oil change too.