Put mine in the '85 runner long time ago. Marlins dual cases. Marlins directions were spot on. Had to figure out how to place the second shift lever hole behind the original hole in the floorboard but not a big deal. I used All Pros X member for dual cases which fit pretty well. Had to open up a couple of the mounting holes a little.
The one thing that takes time is understanding your new gear sets and which to choose at any given time. But when that is in your head. You'll be just fine.
Greg Luer '85 4Runner, '89 FJ-62