It seems the front engine mount was fabricated on my existing 235 and not done too well. I suppose the original 228/248 (?) was longer. To compensate for the shorter 235, they welded a flat piece of metal to the front cross member. In the process, the nuts now barely clear the cross member. So, I was unable to remove them. Between the rust and only being too get an open ended wrench on it , they weren't budging. I will grind them off tomorrow morning because I have to return the engine hoist I borrowed. I also do not see any provision for the carriage bolts on the new engine.