There are some things to consider here. If it is the original Chevy motor, it probably has a fiber timing gear on the camshaft. If you do any work on the bottom end, it would be a good idea to replace the gear. Have a look at the rod bearings. They will be babbitted directly on the rods, so if the bearing surface is worn out, they have to be repaired. Usually the best route here is to have them machined to take insert bearings.
The motor should turn freely without the head. I would guess that the pistons and rings need some lubrication. You can also lubricate the main bearings by driving the oil pump with a drill.
Last edited by truckernix; 11/29/2008 2:11 AM.