I've got a Detroit in the front (D60) and rear (14BFF) of my '79. Only been out in sand so far with it, but under power it doesn't want to turn..........but any good locker/posi in the front I believe would do the same. I was under low lock heavy throttle when I say this, so keep that in mind. Now, as soon as I got off the stupid pedal, the thing went exactly where I wanted it to go.
Depends on what you want for the truck, as with any mod. If you live in snow/ice country, a Detroit might not be the ticket. I built this thing (or should I say 'am building', cause it will never be done) to wheel primarily in sand and to be bulletproof. I was sick and tired of my Auburn rear posi that my motor's torque could defeat in the dunes so that's why a Detroit went in both ends. Guaranteed it won't slip.
Would I do a front Detroit again? Ask me after winter and I make a couple of snow runs up to Mt. Hood. For sand, the answer is a definitive YES.
<font color=blue>'79 ONE TON TPI K5 - See it at---><a target="_blank" href=http://www.blazzinor.rockcrawler.com>www.blazzinor.rockcrawler.com</a>