Ouch, No rear cooler on 3 inch will be hot. My Doo Race 880/3 inch gets hot with two coolers.I have ported just to allow snow to get slung up into the cooler, Does Help, Water wetter dropped 10 degrees or so.
I think you misunderstood my post; the Polaris by design has two coolers that run the full length of the tunnel (regardless of track length). There is no additional rear cooler on any of the standard or PRO RMK's.