On page 110 of Early Buddhist Metaphysics, Noa Ronkin is writing about the Sarvastivadan concepts of svabhava and svalaksana. "To have a svabhava is to be a primary existent. Hence the svabhava is the determinant of a dharma which is dravya, a substantially real entity, and is what defines a dharma as having primary existential status regardless of its temporal status."
Page 111: "Bear in mind, though, that the Theravadins did not subscribe to the Sarvastivadin metaphysics: they did not incorporate the Sarvastivada atomistic theory directly into their system, and rejected the claim that the dharmes exist as past, present, and future. Most importantly for the present context, they did not use the category of sabhava to denote dravya and rejected the very Sarvastivada equation of a dharma with dravya."