Motor dies after startup.

The old fuel and varnish will definitely continue to seize the valves in the valve guides. I assume your two bent pushrods were probably for the two middle intake valves, or at least for two intake valves. I had to compress my springs, remove them with rope in the cylinder, remove the valve seals, soak them in chrysler penetrant for days to get mine free. I also pounded them down too far to get the springs back on and had to yank them back out with the valve keepers back on the valves and a vice grip on the keepers and a rope tied to the vice grips and the other end to a hammer slide. Fun times. Get a new tank and a fuel line from right stuff detailing, stop wasting your time.