Nice buggy and welcome to the forums. You should see some temp changes but probably not huge. You should still tune by the smoke coming from the pipe and how it feels/sounds. My buddy put a crazy nut racing head on his motor once that lowered the temp alot and he would always run it lean just because it temped lower. But you could hear it was lean and insane power. He quit the hobby though so I never got a chance to see it blow!
Was it worth it? Well if you like it yes. If you had a very small or onroad like head before then yes. I think it looks pretty sweet, and that's half what this hobby is about!!lol
Just pay attention to your motor, and remember you're always better off running rich than lean.