how does a 318 engine run if timing is off ?

I'll put money on it being a fuel supply issue.
Did the fuel pressure gauge hold steady at 6 psi, or was that just an initial reading? Did the pressure drop just as the engine began to die? It's easy to make the mistake of thinking the pressure drops because of the engine dying, when it could easily be the opposite- the engine is dying as it runs out of fuel.
Check your fuel line from the tank up to the filter. I know, I know- you've got a new filter on it and it's full of fuel. The problem is that if the pump can't draw enough fuel, it won't displace the fuel in the filter. The engine will slowly sputter and die as it empties out the last of the fuel in the carb bowl(s).
An obstruction in the fuel line can cause the pump to empty out the supply line, but still allow enough fuel to pass and refill the line after the engine hasn't run for a few minutes.
To do a quick check, disconnect the fuel line going to the pump inlet, then attach a foot or two long piece of 5/16 fuel hose to the pump and drop the other end into a gallon fuel can. Then fire it up. if it stays running now, you've got a restriction in your fuel supply from the tank. Check the line for kinks or signs of having gotten crushed. Check the rubber connections for deterioration (which can be internal as well as external), ethanol does not play nice with old rubber fuel hose. Heck, just replace it with new hose regardless while you've got it apart. Try to blow air through the fuel line with it disconnected. Internal corrosion can cause blockage. Resist the temptation to blow compressed air backwards through the line with it still hooked to the tank- you could dislodge the fuel sock from the pickup tube and cause other issues.
If it still won't draw fuel out of the tank, it could be a clogged filter sock.
Hopefully you've just got some deteriorated rubber connections, and you'll be back in business.
That's all I've got. Good luck!