Since its been sitting for so long, pay extra attention to rubber components ( hoses, seals,etc.) with lack of use they will often fail. Not a bad idea to inspect your tires carefully and while your there take a good look at brake lines for leaks and cracks. Then drive the piss out of that Z.
Drop or drain the fuel tank. Don't try to start it with the old fuel in place. Change the fuel filter and get as much out of the fuel line as possible.
Of course you will want to check hoses, drain the radiator and block and refill, replace the battery, and (before you drive it) replace the tires.
Pull the plugs and shoot a bit a bit of oil (not much) into the cylinders. Turn it over with the plugs out to distribute oil in the cylinders and eliminate any extra oil. Do an oil and filter change (consider pre-oiling the filter) and again, without starting it, turn it over for 10-15 seconds times to get oil into the filter and oil passages.