What sort of usage ? what tyres ?

And as important...what sort of ratios do you need ?

And if you're talking about a 2wd gearbox first..and something you can then use with 4wd...you're really limiting your options and a TKO isnt going to lend itself in that direction without lots of custom fabrication work.

With such flexibility in mind, buy a Samsonas. They've adapted their "RWD" sequential gearbox for various applications both rwd and 4wd although the transfer box section is quite bulky.

Photo of it in an R33/34 type Skyline application in the foreground and in the background as a more generic rwd application.

But yes it is expensive, but it will give you the flexibility to chop and change at a later date. Tractive may offer something similar ?

Or for more conventional stuff there are many strong boxes available in the US although a lot of theirs feature a 1:1 top gear if that would be ok for you.
The video is a few years old but still very informative.


The photo is their own transfer case housing, they've also done it with Skyline parts, I thought I had a photo but cant find it