i am in the process of changing thee clutch in my 72 240 and the flywheel has some cracks in it. Should i have it surfaced or replace it? If i need a replacment where is the best place to get one. does any have one for sale cheap.

Have your machinist look at the flywheel, they'll tell you whether or not you need a different flywheel.

If you need a flywheel you can either spend big bucks to get an expensive aftermarket lightened one, or find a used OEM one in a salvage yard. If you can't find one locally, look in the Tech Articles forum for a thread called something like "Used Z Car Parts Sellers". One or more of those businesses listed will be able to help you get one.

I don't believe that new OEM flywheels are available, and they would be expensive anyway.

Those cracks were caused by heat. Depending on how deep they are will determine if your flywheel is reusable. The machine shop will have to remove enough of the surface to leave you with a smooth face. If you have to remove to much then the flywheel will be too thin and will overheat even more.

http://www.arizonazcar.com/fly.html

I have this flywheel and love it (turbo size). It is not nearly as pricey as some of the other light ones on the market. If you cannot get your FW turned then I would think about this one.

Can I put a 240 clutch on a 2+2 flywheeel or do I need a different clutch?

The 2+2 Clutch is larger diameter than the regular 240Z clutch.