I would use the oil pan you now have as-is. Before I'd cut it up, I'd butcher the x-member. But before I'd do either
, I'd get the right
7 qt. pan for the application, like HERE.
Same "footprint", good depth- I'd not run 7 qts. in any 7 qt. oil pan, instead run 5 and get the oil the heck away from the rotator. There's no advantage in running the oil pan full, that defeats the purpose, IMO.
Those wide, flat pans are not my first choice, unless ground clearance is a big issue. The oil still will end up close to the crank and is harder to keep the pick up submerged w/o proper baffles, gates, etc.