you need to be very , very careful when ordering parts for any jdm machine as they not allways the same as similar machines.
7001 and 7100 are very similar, but, not the same machine .
the rear axle/and geaboxes are very similar in a lot of respects but the inner parts can and do vary widely .
i have three 7001 rear ends and two 7100 rear end, only the two 7100 are the same , the 3 7001 all have differing parts from the 7100 and are not readily interchangable, i tried numerous combinations without success.
gear shaft vary as do gears etc.
Dont rush into this, do some ground work and source the right part if you can from a 7100, failing that, best option is to match the part visually if you dont have the correct part number.
I have been through all this parts issue matching jdm to other machines, its a bit of a minefeild to behonest and can easily cost you more in the long run.
hope you find the parts.
rob