I found a box of rod and main bearings someone gave me about 10 years ago. He thought they were from a 200, I need some for a 250 now. I poked around, and it looks like the rod bearings are the same, but I see several options for mains. Different years used full groove, or no grooved mains. What are the differences? Can any be used? I haven't put them in to see if they fit yet.