The 4 bolt main could definitely be a problem. Those pans are pretty damn thick. It depends where they added the material though. Probably on the outside. Should have enough material there to clearance it though. Make sure to check it really well. They fit like ass. Took me 3 hours to clearance one to fit a windage tray.
well that is what trial fitting is for.
first figure out how much you will need to grind off either the main cap, the pan, or both. then use a dremel grinder to shave just enough for clearance. i would grind on the main cap rather than the pan especially if you have just a small amount to take off.