I have a slight problem, where to start? I have a67 fj-40, I need 68 or newer diffs. I found a set from a 81,he whoud like to keep the disks off the 81 for his 68. I have all the parts for a mini truck convertion, I know thay will fit the 68. Will they fit the 81 housings? It's a big parts swap the two of us are doing to help each other out . He wants to keep his as close to stock, gears and tie rods. Mine is a big mod so gears, and ties need to be changed anyway. Will this work? ??? ??? ???