The Matsuba's rock. Made in Japan, great applications for Land Cruisers and they are robust. We've got customer racing on them, customers driving around the world on them and thousands and thousand of daily drivers. Zero complaints!
You would need to buy fine spline flanges. Your existing 10 spline won't work on aftermarket gears which all use the later model 27 spline.
We have an easy solution:
https://cruiserteq.com/pinion-flange-27-spline-fits-1958-1-1978-fj40-55-w-aftermarket-27-spline-pinion-gear-applications-pn35021/...