Long time since I posted, but I've been lurking...
Anyway, I finally decided the bench seat in my 89 2WD standard cab truck was just too uncomfortable. I was lucky to find two 4Runner SR5 buckets in the grey that matches my interior. I believe they were from a 2 door 4Runner as they tilt forward, as well as recline.They came from a low-mileage, non-smoking vehicle, and look damn nice.
Installation was sooooo easy! I did not have to drill any holes at all. The inboard front mounts lined up with holes in the raised rectangular stamping on the floor, but there is no threaded insert there. I got around this by epoxying a nut to a flat washer for each side, then epoxying this into the mount area. Careful not to get epoxy in the threaded part of the nut! I let it set overnight, then replaced the newly-washed carpet in the truck, and proceeded to mount the seats.
The rear mounts on the outside lined up perfectly, and on the inside of each seat, I simply used the seatbelt anchor threaded insert. I mounted the seat and the seatbelt inner sides to the same bolt. Except for the somewhat ratty looking seatbelt inner sides, it all looks like new from the factory.
A treat, and the seats are so way much more comfy than the old bench.