I recently bought a '79 Z28 w/96000 miles. All original. I decided to take it from NYC up to the pocono mountains over the weekend. So ihad about 3/4 tank of gas in itwhen istarted out on the 125 mile trip. Everything was going well for the 1st half of the trip(even getting stuck in a little traffic). But when my gas gauge got around half a tank, the car started "boggin out' and seemed like it wanted to stal everyso often. Now this was driving at around 70 MPH. So i kept driving and noticed the condition was getting worse as the gas gauge was getting lower. So I thought that maybe the gauge was broken and i was running out of gas. So i stopped at the next gas station and filled her up. The problem stopped. So I tought. Then happened again when the gauge got to half again.( which was about an hour of driving highway speeds). I don't know what it is. I'm thinking maybe it's a fuel pump or even something simple as a fuel filter problem. Changed the plugs & wires(and made sure things were in the correct firing order) changed oil & distributer cap & rotor prior to the long trip. Any ideads? Appreciate the help

 

When you filled the tank from "half" how many gallons did it take? Are you still sure your gauge is accurate? Since you probably don't know the age of the filter, change that. And if the capabilities of your fuel pump is marginal, it could be having trouble pulling the gas out of the tank when the level is lower. Since liquids "seek their own level", with a full tank, the gas will be practically running out of the fuel line on its own without a pump.