I've fixed that same issue on two different cars. First was a 66 mustang, 200 i6. The fix was a float issue, I took the carb apart and reset the floats. Problem solved. The second car was a 71 comet, 302. It had the same issues and the fix was replacing the coil. No issue since the coil was replaced. The next time it dies on you immediately check the coil for spark to rule that out as others have said. Good luck