We are rebuilding my nephews 340 and I’m not sure about the crankshaft drag. The book says it should turn by hand with the neoprene rear main seal. After all the caps were torqued to specs the crank will turn by hand but only after it is started by rotating it with a ratchet on the damper bolt. If it sets for a little while it can not spin it until you start it with the ratchet again. It doesn’t feel like it anything is binding but it is snug. Any help would be appreciated. Thanks………..