You would have to re-galvanize the frame. I would get a steel frame, weld in whatever mounts you want, test fit it and then get it galvanized. It isn't very expensive to have it done.
I think if someone could get the Cummins R2.8 to work with the 2.5/200tdi mounts it would make an easier choice for many. I have a galvanized 200tdi Rovers North frame and wouldn't want to cut engine mounts and weld new ones in and I'm sure I'm not the only one.