To my knowledge, there are two types of covers, but they both will accept either a right or left side inlet water pump.
The only big difference in the covers that I can remember had to do with the location of the
oil dip stick. One model has the dip stick hole in the cover, and the other does not..... the dip stick enters the pan from the side of the block. I think later 5.0 engines used in cars and explorers had different covers too, but I thought the bolt pattern on the pumps were all the same.