Got a fire Raging Bolt + Iron Boulder team for you, had fun with it up the ladder to the 1900s in testing. These are the most successful versions with some more heat versions in the replies:
https://pokepast.es/59486a29147683fd
https://pokepast.es/10c732e2a76a526a
https://pokepast.es/59486a29147683fd
https://pokepast.es/10c732e2a76a526a