A strong box is basically a double transfer case, but i had Jake build mine for the old tried and true ford np 205 which has two shift levers, that makes it possible for me to grind the shift levers so that i can have front wheel drive, this is great for front digs in tight places to turn around. All you do is lock the rear brakes and put it in front low or high and hit the gas, and you can turn on a dime. So basically the strong box is the stock ford 1354 4 low ratio and then i can put the np 205 into low also and get a great lower ratio, plus i have 6.72 gears in the rockwells so i should be at a great crawl ratio, i had behemoth drivetrain make my box, a billet front bearing retainer, a rear out put support ( because that np 205 is heavy) and all cable shifters. **** is in route and i cant wait to wheel this pig. i will keep the site updated, i also got sponsored by a local team here that makes drag cars that want to get into **** like the hammers, so they are making my cage and that is awesome. Im very stoked i have seen a few explorers on rocks but i think this one is quite a bit different.