Wheels and lug nuts?

["Paul" <9laser3@bright.net>]

  I have a set of after-market wheels, brand unknown, 14" x 5.5", that
recently came off a 280Z that I would like to use on my 1969 1600 roadster.
The wheels came with a shouldered lug nut so I know I can't use stock ones.
Are there lug nuts available with the correct threads that would work or is
it necessary to install new studs on the rotors and drums?

Paul Kort
Ohio
1969 KA24E roadster