The issue with bolting 4runner seats into a 1st gen Tacoma is mostly related to the outside rear mounts. These are 1.5" off from the stock floor bolt hole. The front mounts can be easily bent to match up the the stock holes, but this outside rear mount is just too far away.

You can see much more information about these on Tacoma World here: https://www.tacomaworld.com/threads/4runner-seat-adapters.622390/

This is a complete kit for 2 seats including
(2) powdercoated brackets, (2) grade 8 carriage bolts, (2) washers, (2) grade 8 nuts.