I have a 04 summit HM with a 800 HO motor that I blew up bad last year. I am going to Hay days snowmobile swapmeet in Minnesota next week to look for a replacement engine. anyone have any suggestions on what to replace it with? I am thinking another 800 HO with a big bore kit. Will a 800r engine fit and is that option better or worse? I would like to stay somewhat stock as far as keeping the reverse, the oil injection, and DPM. Is there a difference between the motors with RER and non RER? Thanks in advance, Matt.