Car Quits At Speed :( stressed

I had similar issues with my 1968 Barracuda when I first bought it from a classic car dealer. I thought it was the ignition, but it turned out to be a fuel issue.

The fuel filter was completely clogged. It was the weight of a baseball, when a new filter weighs nothing. However, the car still ran like crap.

I rebuilt the 2bbl carburetor for the 318 engine, and holy crap, the engine came alive. I unintentionally laid down a strip of rubber when I stepped on the gas pedal.

Do not discount the fuel system. A carb rebuild kit should be $30 or less, but they may be hard to get locally depending on where you live. There are always online parts stores that carry the rebuild kit. Remember to get carb cleaner, I recommend at least 2 spray cans, and rubber/latex gloves. You do not want that carb cleaner on your skin. An air compressor is also important, since you want to use the compressed air to blow out any debris that the carb cleaner will loosen up.

Edit: Never mind. I see where you said you cleaned the carb. Was it just an external cleaning, or did you take out the carb and rebuild it?

Good luck.