All engines must be drained with pans off and filters removed.
All units containing fluids, such as oil, hydraulics, transmission fluids, gases, etc., must be properly drained.
Valve stems must be removed from cylinders and preferably a hole punched in the cylinders.
Any tank other than hot water tanks or water pressure tanks must have a large hole cut into each end of the tank for visual inspection.
All transmissions must be drained of fluid, pans off and no torque converter.