An upper mount assembly for an air-over vehicle suspension system includes an annular elastomeric isolator molded between two tubular bushing sleeves and press-fit into a through bore defined in an end cap. The inner bushing sleeve is adapted to receive the free end of the system's damper rod while an axial projection of the end cap is supported for relative rotation within a complementary through bore of a top plate. An axially-projecting lower surface on the elastomeric isolator defines a low-profile jounce bumper adapted to resiliently engage an upper end of the damper's cylinder body, thereby obviating the need for a separate jounce bumper while further accommodating relatively-low vehicle ride heights.