Any oil will do- - - -preferably something that will have a little viscosity to it, not one of the water-thin synthetics. Do a LOT of preparatory work before you even think about turning the crankshaft, however. You're going to need to remove the spark plugs and soak the cylinders with lightweight oil such as KROIL or Marvel Mystery Oil to hopefully prevent scoring of the cylinders as you try to wake up the engine. Ditto for valve guides- - - -soak them liberally for several days and work each valve individually with a pry bar so they won't stick and get bent by a piston. Inspect the intake and exhaust system for any evidence of rodent nests - - - - -it's amazing how small a hole a mouse can work its way through to make a nursery out of a manifold or a cooling passage. I pulled a cylinder head recently, and found a nest in the cooling passages between #5 and #6 cylinders, and the only way to get there is through the thermostat housing!
Pull the distributor and spin the oil pump with a cut-off screwdriver blade in a 1/2" drill motor to prime the oil galleries if there's no evidence of extreme sludge buildup in the oil pan. If the engine is really gunked up, pull the pan and do a scrubdown of the pan and a pressure wash of the crankcase.
Jerry
