Is this enough space on my rear wheels? 18” wheels

Any rear disk kit will act like a 1/4" spacer or so, due to the slip on rotor.
Just talked to Forgeline and since I will be changing both halves they can send me the two sealed replacement shells. It's as simple as unbolting the face and making sure it's cleaned of the old sealant and prepped with alcohol, mating the three pieces, and torquing the hardware in sequence.