1986 Nissan 300zx and want to add a turbo what modifications will need to be done?

depends on how much you are willing to spend, i would definilty consider swapping the older motor for a newer 89-92 300zx motor that already has twin turbos and are easy to work on.

it you want to stay with the stock motor, you will have to first off get a custom turbo manifold, piping and intercooler.