We replaced the driver's and added a passenger/copilot chair in our 2000 bluebird 4-window shorty with captains chairs from a 1980's Ford Conversion Van.
YouTube Video of Install
Both were simple installs. Find where you want the seats to sit, ensure they are flush with the dash and cab in general, then drill holes and use grade-8 hardware to secure the seats. My seats are more securely fastened now than they were with the stock install.
Keep in mind where the seat will be when adjusted either front and back or swiveled. Also, consider how far back you will need the seats to slide to access your doghouse/engine from inside.