Purge fuel system of any old fuel. Remove spark plugs (and ground them) before turning engine over by hand to check it rotates smoothly. If you have a bore scope, check the cylinders for any obvious issues, particularly corrosion.
Plugs back in, attach good battery, add fresh fuel, prime carb’s with a little fuel down the throats and hit the starter. I would do this outside as I’ve had the odd backfire trying to revive old ‘ski’s and a fireball in the garage is not the best way to start your day.
