You can get more power with race fuel but it really needs higher compression to take advantage of its potential. You may make a few extra Kw's at best with your setup.

Better mods would be fitting a very good cold air intake to the carbs and run the smallest wheel tyre combo you can.

Run a colder plug such as NGK BP7ES and set the gap to 1mm. Total ignition advance should be around 36 degrees on a 95 RON fuel.

Set your tappets to 0.014" inlet and exhaust and make sure this is done accurately even though they will be a bit noisier.

This should help a bit.
Good luck.