I have a 1998 Corvette with 42k miles. Recently the fuel gage will drop to empty after filling the tank and driving for about a half hour??.. Is the a Fuel gage Fuel Pump, Fuel filter Problem? or..? Dollars to repair..?

I had the same problem with my 98 Corvette with 69K miles. Mine did exactly as you described soon after I purchased it in November of this year. I went online and read posts of others with the same problem and how to try and fix it. At 1/4 tank add 2 bottles of Chevron Techron cleaner and fill up with good name brand premium fuel. The Techron cleaner will clean the sulfur residue and other contaminants off of the fuel level senors in each of the left and right hand side gas tanks (C-5's have two gas tanks on either side connected by a transfer pump with each side having it's own fuel level sensor). I did this and so far after nearly 3 tankfuls there's been no recurrence of the problem. However, if this doesn't help then the alternative is to replace some if not all of the components mentioned earlier. I got a $1300+ repair quote from my favorite garage prior to applying the above fix. I'm no mechanic and I may have some of the actual part names incorrect. I hope this helps you out and fixes your problem! BTW, you can also use a full can of SeaFoam cleaner in lieu of the Chevron Techron cleaner. I used the two bottles of Chevron Techron the first tankful and used SeaFoam in the second tankful. I plan to use a bottle of SeaFoam every 3-5K miles to help keep this problem at bay and keep my fuel system cleaner!