I would get a complete overhaul gasket set,and a service manual.
Rings are checked for clearence in cly bore before placed on piston. they have a this side up ect on them.
The lifters should be replaced in same order as removed. New cam & lifters it doesn't matter, used have allready worn in on cam & lifter bottom.
If it turns over hard by hand or drags that is useually caused by drit on a main or rod bearing they must stay clean when assembled.Remove all piston turn motor see if drag is on mains. then Do one clynder turn motor do next turn motor. good luck Bill
