Hey, I'm new on this board but I just went through the same problem with my chevelle, oil pump locked up.

Pull the engine if you have a hoist...

If not unbolt your tranny and slide it backwards. You can then jack the engine up high enough so that you can get the oil pan to clear the flywheel and the front crossmember. You need to jack the engine up about 5 to 6 inches in order to get the pan off. You'll need two floor jacks, several pieces of 2x4 and lots of elbow grease.... don't over torque your pan bolts too!!! Good Luck.