If someone knows who are the best Delta Pokemon users of stealth rock, it would be very nice =)
The first that come to mind are the Delta Regis (Regice, Regirock, Registeel). Registeel is especially neat because it can set Fire-type SR, although Fire M-Steelix can as well. Regice is, too. That’s because it’s got that neat 200 Base SpD though, plus Storm Drain and some good defensive options in Scald, Recover, T-Wave, etc. Delta Goodra works well, too, albeit with fewer defensive moves. Spidergross works too; it’s great as a lead in general because its gets rocks AND Web AND Toxic Spixes AND U-Turn AND Poison Heal AND is wonderful offensively too. Ruingross can use rocks too, but IMO Spider is better at the lead/utility game, while Ruingross is better off with a “rocks + 3 attacks” set, if you go with that at all.
Apart from that, I struggle to remember other Deltas that get SR. Delta Greninja gets Spikes + Prankster, which is neat, but you asked for rocks, so I’ll leave it at that.