http://www.top4runners.com/ja/runhist3.html

This website gives a good breakdown of the options available to and the differences between the different generations... of course, as with everything else on the 'net, I can't vouch for its accuracy, but it is the reference I use...

Now, from my memory of reading this, the e-locker was only available with 4x4 4Runners, and I think that's the only limitation. Again, though, that's just from my memory of reading at that website...

Don't go to that website unless you're ready for a LOT of information!

1993 YJ S, 2.5L I4, 5spd
30x9.50x15 TAKOs on 15x8 American Racing Rock Crawlers