Those are good parts for the conversion. We also carry 1000 Watt versions of the motor and controller for a little extra power.
A note and warning to anyone else reading this is that these parts require custom installation and are not bolt-and-go or plug-and-play with the existing parts on the Dirt Quad.
Looking at the other topics I pulled together the following parts for upgrading a Razor Dirt Quad from 24 volt to 36 volt. Can you confirm if these are the correct parts or if their something that would work better.
MOT-36800B 36 Volt 800 Watt motor
SPD-36800B 36 Volt 800 Watt controller
THR-86 twist throttle with 36 Volt battery meter