These are fine spline. I bought these used from a guy on mud who bought them new and ran them in his fj60 for a number of years. When I took them to the shop to replace my 4.88s, after working on it a while, the tech told me one set of the gears had been setup with the pinion a little too deep. If he set them up correctly they would work fine but be noisy. I ended up just getting new gears. Just want full disclosure on what I am selling. I will sell both sets shipped for $70 total.
