Need advice. Car was not running very smooth and gas mileage was stupid. Replaced the following: air cleaner, fuel filter, spark plugs, spark plug wires, distributor cap, points, condenser. Still ran bad. Found out distributor bushing was worn and replaced including new vacuum advance. Car ran great for 2 days and distinct improvement in gas mileage. But started to get worse and worse. Continual stalling. Backfiring through carb. Readjusted timing and carb several times and runs great for a couple miles, then gets bad very quickly. Has been suggested that I got a bad distributor from Autozone. Any other suggestions and ideas would be welcomed.