What procedure should be followed to restart a stock engine that has been sitting a while...like 10 years or more? Just the mechanicals, Not FI, Not electrical etc.

Here are my thoughts, what else should be done?

Engine
Drain engine oil, install new oil filter
Flush crankcase with 2-3 quarts of Marvel mystery oil, drain
*check for internal corrosion
Fill crankcase full of Marvel oil, let soak for at least a month (How much Marvel oil will fill the case?)
Drain Marvel oil, install new oil filter and fill with motor oil
Replace pushrod tube seals, valve cover gaskets
Hope that rear crank gasket does not leak, replace if req'd
Check for leaks, repair leaks
Check/adjust valves

Transaxle
Drain trans oil
Flush trans with 1-2 quarts new oil, then fill
Hope front trans seal does not leak, replace if req'd
Check for leaks, repair leaks

*I may have access to a borescope from work that may get me get into the gas tank, cylinder chambers and any other orifice to check for internal corrosion, cylinder scoring etc and will do that if I can borrow the scope for a weekend.

clean the gas tank.
If it turns by hand it will start.
I revived a 356 motor, sat in a barn for years...10 at least.
New oil, new ignition, rebuilt carbs, (I used a plastic gas tank from the mower hanging from the ceiling)
rebuilt fuel pump...
done, fired right up and its fine.
I would skip the marvel mystery oil unless it wont move.
Just put fresh oil in it and clean the fuel system.
The worst thing is to suck in bad old rusted fuel on the first two or three strokes.
Assume the tank is rusted...they all are.
Rich

remove old fuel filter, flush fuel lines (you can use brake cleaner for that), install new fuel filter, clean gas tank, clean air filter, flush fuel pump and verify that it still works ...

Andy

Marvel is most likely overkill... I would maybe pull plugs and squirt some oil in and hand rotate the motor first though. I would do a 500 mile oil change...

Same deal on the trans... I would drain, and fill run 500 miles and drain/fill again.

The thinking behind using the Marvel oil fill and flush, and especially in letting it soak, was to:

*Penetrate all the nooks and crannies inside the case, flush out old dried oil deposits, before new oil is installed, especially at oil galleries and between adjacent moving parts – bearings, bushings, piston rings/cylinders etc.

*Loosen up corrosion and flush it out before it causes damage.

*Prime oil galleries and the oil pump that are empty or dry

*Saturate all engine internals in a low viscosity lube as a prelube between any moving metal parts to prevent or minimize damage during those initial rotations, before the oiling system will function. Cam lobes, bearing surfaces, piston rings/cylinders, valve guides

*Find oil leaks early before they become big leaks

*Saturate seals at rear crank oil pump and oil cooler that may be dried out

After this cleaning/soaking process, before ignition, the engine should be cranked over 10-20 times with the final oil in it, to get the oiling system functioning.

Still think this is not needed?