If the 840 is tuned properly and the cat is stock, the 840 should smoke it!! I can run right with a can am 800 Quad in 500' with my 840. I think the can am and cat 1000 quad are pretty close in 500', the can am might even be a little quicker, so add the extra 400 lbs to the cat sidexside and it shouldnt be a problem. I dont have any first hand experience with one though. There is a prowler in our area but we havent met up YET! My buddies claim that thier stock RZR S runs right with it and I can kill a RZR S!
08' Teryx LE, FST 840, Muzzys, VDI, Dalton, VFJ Roller, Thunderhawk Performance Race Cage, Bumpers, Door Bars and Bracing, Beard TSX Seats, 5pt. Crow Harness, 12" ITP Type 7 Beadlocks, GBC 8 ply Dirt Commanders, Pro Armor Skids, Team Green Plastic
08' Teryx, Maier Orange Plastic, Thuderhawk Performance 4 Seat Cage, Bumpers, Door Bars and Bracing, Beard TSX Seats, 4 pt. Harness, 14" Chrome Doughas Diablos w/GBC Grim Reapers, VDI, Dalton