Chevrolet Repair: Bad Gasoline Possible??, chevy camaro, overhead cam

Question
Hello:

I have a 1996 Chevy Camaro.  3.4 V-6 Engine.  147,XXX miles.  I think I have some bad gasoline.  A week ago, I driven this car the entire week without any problems.  Friday night after work, I filled the tank for the following week.  I didn't drive this car the entire weekend.  It stayed parked in the garage.  I didn't go anywhere or even start it.  On Monday as I was out driving to my destination, the car started shaking as if it was going to cut out on me.  It drives really rough.  Prior to me filling my tank, the car drove fine.  I have had this car for almost 9 years, and it never have driving this badly.  Today, I drove it around, and it started backfiring.  I am still on that tank of gas.   I don't drive this car much, I have two cars.

Bad gasoline you think??

Answer
most likely, its not bad gas. backfiring indicates a blockage, or ignition timing problem. this 3.4 litre, is it the overhead cam, or pushrod engine. i really have to know before i can tell you where to go with this. if its the overhead cam, does it have a distributor? get back to me.