polairs

I recently bought a 1995 polaris xlt 600 triple with slp pipes and triple air filters. It sat for around 15 years so that give you an idea of what things look like. After cleaning out the gas tank thst the gauge had rusted in and soak cleaned carbs and doing fuel and oil lines I got it running...

Is it a direct swap between an 800 motor in a 04 RMK 144 track to an 600? If not what else will I have to do? Change gears?