Today I swapped interiors. Everything went alright, except the seat belts. The center belts come between the cushions on the 80, and on the 89 they come through a slot cut in the bottom cushion. The mounting holes are also a few inches apart. As it sits I have the 80 center belts in the 89 holes, which gives very little room to buckle. I'll figure something out.
Here's a few pics.
Here's all the stuff in the new truck.