I have daily driven a lunchbox locker in a samurai, mud tires, no weight, lockers, soft suspension, manual transmission. Worst possible situation for icy roads. It takes a different driving approach, you simply cannot drive it like an open diff. If you do you will crash.
I have also driven a blazer on mud tires with a Detroit. Same deal. Much lighter on the throttle, much more finesse needed than an open diff.
There is no doubt it's much easier to drive an open diff on ice. Given the choice I would absolutely buy a selectable locker. But also given the choice I would run a lunchbox locker vs a factory limited slip or aftermarket for that matter.
I still mantain a front locker will help substantially more off road than a rear locker.
In my experience with a quadrajet specifically I needed a locker to get into a situation where it died. Open diffs would just not let me get far enough. But my quadrajet was tuned in nice.
A locker will allow you to get into situations where fuel injection will be needed. Do which to do first?
I'm a traction kind of guy. You can't go anywhere without traction, with a locker you double your traction.
With fuel injection you certainly have some increase in ability and better overall driveability, but it's not really going to allow you to go additional places off road.
Now that is speaking specifically of off road. If this is a fire road truck, that will rarely see harder obstacles why lockers at all? Limited slips both ends ( awesome on ice in 4wd) and a good winch.
I used to be a recommend lockers every time all the time. But limited slips do a decent job with all tires contacting the ground.
