+1 Sharps;
There is no locker for the front on the 1998-1999 because of the 194 FIA front axle.

However there is a locker available for the rear axle.

 

ok, so my best bet is to save up my money and get a detroit locker for my rear diff then... how much will that help with offroading?

 

A rear locker will get you out of quite a few nasty situtations. But so will a good set of A/T tires too, but then you loose a smooth quiet ride on the street. Just all depends on what you want to do more.

 

well ive already got a pretty nice set of A/T tires on my rig... they're the stock size for my rig... 235/75/r15... i have BFG All-Terrains on it

 

Sounds like you're all set then. It's always good to known as the guy who if he gets stuck...well nobody's going home. You may want to look into adding a little t/s bar and shackle lift to your D if you haven't already, it's cheap to do.

 

yeah... im lookin into doin the t/s lift here soon to my rig... just gotta get the parts and find the spare time 0.o

 

what kind of affect would having a locked diff have on city and highway driving?

 

Bad things, when you turn your rear wheels will skip because the outside tire always needs to spin faster than the inside one. Only if you have it locked of course, when it's unlocked it's fine.

 

your already wonderful gas mileage will take a big beating

 

Not true! As far as taking a big beating, no it doesn't and I wouldn't even go as far as to saying it will take a beating. I just got my Detroit Locker installed last week and have notice a very slight decrease in fuel economy on the highway. Keep in mine that the locker sends all power to both wheels rather than one or the other so that means you won't have any wheels spinning freely that you don't want spinning.

Get a detroit locker. A detroit locker unlocks itself when you let off the throttle (around turns, etc.) so will be like an open differential when you're not on throttle so will minimize wheel slide when going around turns.