That looks like a pretty decent Suburban
What I would suggest, before you start tearing things apart is try and diagnose the engine. Have you checked the oil? Is there any signs of water in it? Is there coolant in the radiator? If not add some water and see if it stays full. Pull the spark plugs and inspect. Connect a battery and see if the engine will bump over, don't crank it, just see if it will move a little. If it does and the coolant stays up then I would squirt some Marvel Mystery Oil in each cylinder and let sit for a day or so. Meanwhile, drain the oil, change the oil filter and add some inexpensive oil. Also disconnect the fuel line either from the frame to the fuel pump, or from the fuel pump to the carb. Then with the plugs out and the coil wire disconnected crank the engine over a few revolutions. If all seems good, continue cranking until you either shoe oil pressure on the gauge or the oil light goes out.
I'll shorten this up a little. Once you have oil pressure, do a compression check. If that checks okay, then I would change the points, condenser, rotor cap, wires and plugs. Squirt a little gas down the carb and see if it will fire. If so then you will need to go thru the entire fuel system from the tank to the carb. If you need some more detail on those things just ask.
Or you could bypass all of that and just swap the engine for a known good running engine. It might be fairly easy to find a decent running 350 or even a 305.
That cable is a limit strap incase the engine mount separates, which this style of mount are prone to separating.