Hi Tim, it's good to hear you working on this one. I find that medium tempo gallops are always fun to play.
Ok, onto the details. You obviously already know to play the gallops on one string only whilst hitting the occasional power chord on the changes. That's good. Sometimes the chords don't sound full enough, as if you're only catching the root note.. so just try to get the chords sounding more full - make sure you're catching both strings whenever there is a power chord. You probably are playing it right but your picking might not be consistent enough when you need to hit 2 strings.
Other than that it's just a few timing issues here and there when you change position.
You're already doing the right thing by using a mild distortion instead of totally saturated gain. This is good, it means you can hear what you're doing.
Try to work on those areas I've highlighted and I'm sure we'll see some improvements