These are Cast Iron folks. Hot tank, Wet Magg then Shake and Bake them. Guess what though? Once done with all that cleaning if you media blast them the stuck on grit, gasket sealant, gasket material and other material off, it will will show up as dark spots. These spots are usually stuck on grit waiting for a bolt or careless mechanic to shove it into the internals of a used to be clean tranny
