Rusty water jackets. Engine sitting for 7 years

CLR, Borax, acid (vinegar) molasses...use whatever you want. no need to run motor. Just fill to brim, soak and drain out of Post #2 pipe plugs (my post too) Running motor would just get things hot and moving. Id pull the pump if its still in the car and direct a hose into one side of the timing cover. Youll eject some stuff but most stuff will be on the bottom at the drains. Once you get the motor running (rusty jackets or not) then you can get some caustic stuff churning in there for a proper in the car cleanout. Squirt some oil in the cylinders prior to starting to help seat the rings again. and check oil prior. No use cleaning a motor that will seize if its started with no oil.