Motor dies after startup.

Look for the suggestions on the thread about Avblend...SeaFoam and Marvel Mystery and the auto fluid before the oil change seems to be popular......My neighbor's dad used Rislone down the carb!

You're bending the push rods for a reason; either the rockers are binding really hard (not at all likely). Or something is binding the valves in the guides. Or something is hitting the valves in the cylinders (Bolts in the cylinders? Squirrels hiding their winter larder in your engine? Not likely). #2 seems most likely from all the comments from those in the know.

And 'varnish' may still be slowly coming in from the tank and replenshing the gumminess.

Have you removed the valve cover in the AM and see if all the valves will move? Any recent fill of fresh fuel? Does the engine smooth out after warming up or just get worse? (Sounds like the latter.) The smoking may be from fuel going right through a cylinder via an open exhaust valve into the exhaust.

But my concern is that there is still varnish in the tank/fuel ALONG with the old, bad fule that is detonating and could damage a piston. (That could explain the sounds and the oil smell.) If you can free up the valves and replace pushrods and everything runs smoothly again, then you are OK....for now. But that is why the old gas HAS to be gotten out. I have damaged an engine with bad fuel to where I had rebuild it. All the additives in the world can't fix really bad, old fuel.....