[brighton911]

I would keep the cases in a horizontal position. WD is not likely to help as it is not corrosion that is holding them together but more likely the sealant. Make really sure you have all the cases bolts and nuts off. Two dome nuts in the cooler cavity and the nut in the chain case can get overlooked. There are some extended bosses on the cases near the part line that you can tap on with a urethane hammer to loosen the grip. Do not pry between the cases, it will do permanent damage to the sealing surface. Skip any brute force and go for patience and perseverance, they will win the day. Good luck