0 Atk Rapidash Flare Blitz vs. 252 HP / 0 Def Eviolite Gurdurr: 99-117 (26.4 - 31.2%) -- guaranteed 4HKO breakfast af
252+ Atk Gurdurr Drain Punch vs. 252 HP / 0 Def Rapidash: 156-184 (46.7 - 55%) -- 69.1% chance to 2HKO (20.8 - 24.5% recovered)
252+ Atk Guts Gurdurr Drain Punch vs. 252 HP / 0 Def Rapidash: 232-274 (69.4 - 82%) -- guaranteed 2HKO (31 - 36.6% recovered) if u switch into burn its even better
252+ Atk Guts Gurdurr Mach Punch vs. 252 HP / 0 Def Rapidash: 124-147 (37.1 - 44%) -- guaranteed 3HKO bop
(for the sd set)
+2 252 Atk Rapidash Flare Blitz vs. 252 HP / 0 Def Eviolite Gurdurr: 250-295 (66.8 - 78.8%) -- guaranteed 2HKO (24.7 - 29.1% recoil damage)
252+ Atk Gurdurr Drain Punch vs. 0 HP / 0 Def Rapidash: 156-184 (57.5 - 67.8%) -- guaranteed 2HKO
252+ Atk Gurdurr Mach Punch vs. 0 HP / 0 Def Rapidash: 84-99 (30.9 - 36.5%) -- 60.1% chance to 3HKO
24 + 57 + 30 = dead horse
its worth noting that gurdurr can only switch into sd rapidash once
252 Atk Rapidash Flare Blitz vs. 252 HP / 0 Def Eviolite Gurdurr: 126-148 (33.6 - 39.5%) -- guaranteed 3HKO after Stealth Rock
but being able to block rapidash from clicking sd can help alleviate pressure on the rest of ur team bc of it, but gurdurr still hard counters the utility set very nicely