You might need to widen a couple of holes on the outside of the taillights. You should also swap to an 89+ lock cylinder. They mount up differently than pre-89, so you'll need to mark and drill holes for the mounting tabs. For the lower trim on the center piece, you'll either need to drill a couple of holes through the body so that the studs dont interfere with the body. I personally cut them down so that it all sits flush, but that's up to you.
I bought my lock cylinder, taillight gaskets, and misc mounting nuts from Toyota. Subtotal is probably about 150-160 for all that. I say probably because I got mine for about 140 with tax, but I have a discount...