My 98 durango cuts out or sputters at highway speeds. The tachometer seems to surge from 2- 4,000 rpm during the cutting out. Has anyone had this problem? If so, is it electrical or fuel related, or what?

Yes I am have this problem on 2001 model. Did you find out what was the problem.

could be in fuel system ie. fuel pump/filter assembly need to drive with fuel press gage hook up to fuel rail to be able to see fuel pressure drop off