I would like to extend my 4wd shifter. I think it's like 6inches, I want it around steering wheel height. would welding some rebar work, or buying a longer one. would like some suggestions.

 

What I would do is either disconnect it under the truck by the transfer case, get a smooth bar at you desired height thread it and reinstall it OR figure it the thread pitch in the lever you have now (when you unscrew the handle) make another bar (again make sure it's smooth) tap it to the thread pitch it on both ends get a deep nut screw it on to the factory bar and then screw the handle back on.

 

If the original **** threads on, I would buy a steel tube or solid shaft. Thread the ends and screw the **** back on top.

 

Bear in mind, a longer shaft means more throw(hehehehe, that's what she said :-) ) so your longer shifter would needs to be bent backwards so it doesn't hit the dash.