Do any of you Polaris experts know the build dates of the mid year upgrade on the 97 xc 600 xlt triple or how to identify them by looking at one. They had 2 bearings on pto side, better oiling and slp designed higher compression heads, at least this is what I have read. Supposedly the best of the xlt engines. I am thinking about triple pipes on mine and I don't want to do it unless it's the better motor. Thanks for your help.