Prioritizing upgrades to 50cc GY6

[rsfluffy]

First off, I'm looking for more torque/ hill climbing power not top speed nor acceleration. If those improve as well, so much the better.

So, what mods would you make and in what order?

The first thing I'm going to do is install a tach, so that I can really test any mods and not blow this puppy up.

After that I'm not sure where I can get the most bang for the buck.

BTW, a big bore kit is not an option, I'd like to appear legal at the very least.