Actually I doubt that is an optimal spread as the disparity between Excadrill's defensive stats and its HP means that EVs invested into either one of its defenses (or both) will give it a greater EHP.
I think really only one set is needed to be honest, with a more defensive spread mentioned in AC and a secondary leftovers slash. Also a balloon slash.
Sadly, whilst Sand Force is a very cool ability, Excadrill's unboosted 88 speed isn't gonna sweep dick; Sand Rush is a far better ability.
[SET]
name: Swords Dance
move 1: Swords Dance
move 2: Earthquake
move 3: Rock Slide
move 4: Substitute / Return / X-Scissor / Rapid Spin
item: Life Orb / Leftovers / Balloon
nature: Adamant / Jolly
evs: 4 HP / 252 Atk / 252 Spe
it may have too many slashes but I would like to ask about substitute. Skarm still walls you, Gliscor will wall you without Return, Slowbro walls you without X-Scissor. You won't be able to OHKO Breloom without a boost if you opt to use sub over SD ont he turn it switches in. I can only see it being useful for like Iron Fist Infernape trying to revenge you with Mach Punch.