Man I love the ´70 Chevelle...great car IMO.
For the wiring, well I´m not sure what kind of detail level you´re after but many modelers just drill holes for ignition cables.
Then you´ll have to connect the coolant hose from the radiator to the intake manifold, but that´s all explained in the instructions sheet.
You also could mount fuel lines to the carburator and so on, but what are your plans for the engine, all stock?
Good luck