[mhoward1]

Personally I think you can take either the 240 or the 350Z on your first adventure. The only thing I would do to either is

1) Check for safety. Make sure all the critical parts are in working order, on the 240SX, I would include looking at the Hubs and bearings and the ires you have on there are safe.
2) Make sure you have good brakes and fresh fluid
3) Make sure you have the essentail tools like a air guage and torque wrench.
4) make sure you have personal safety equipment like the proper helmet

Other than that, you just need yourself. You don't need to make any performance modifications to do an HPDE, you just need an open mind, willingness to learn, and an ego in check.