If it fires briefly and then quits... you are close. What type of carb does it have? Is it stock electronic ignition? You might need a new box. Also if it does not start using these technics, you might want to squirt some trans fluid into each cylinder to allow it to increase the compression after sitting for so long. There are three things needed for the engine to fire up. Gas to the cylinder, air to the cylinder and fire from the plug. You have already made sure that the timing was correct and that there was fresh fuel going to the cylinders. So I'd look hard at the ignition system. Distributor, cap, coil, and box. Also make sure you have 12 volts going to the coil. Electronic dist needs 12.5 volts to fire efficiently. Look for fire from one of the spark plug wires with a spark plug hooked to it and placed near a ground. Either have a friend (ex-friend after this) hold this with bare hands nearground or use insulated plyers. But you need a healthy spark. My experience with 340s are they love gas. To start mine I would put almost a cup down the carb to get it to start. I would of thought it too much and flood out. But it needed alot of fuel to start. I hope this helps and HAPPY BIRTHDAY
