Jack, I'm not sure if that one has been tried already. I know the VG30 has been swapped into a 510 with no problem so a swap into a 280ZX should be no problem. You might even be able to use the engine mounts used in that swap. A couple of things you might need to consider:
- The radiator from the Frontier (I'm assuming that's were you'll get your VG33 from) has its water outlets on the same side unlike the one in the 280ZX. You might want to get the Frontiers radiator as well to reduce the fabrication coolant piping.
- You should also consider using an electric fan so that placement of the radiator is not so crucial.
- You will need to fabricate a new oil pan but ensure that it does not stick down lower than the front cross-member, and be sure to make up any displacement that you remove.
- The exhaust should be 2 inch pipe from each exhaust manifold which then join into a singe 2.5" pipe behind the transmission. You's install the O2 sensor in the collector where the two pipes join. Opting for twin exhausts would mean one bank would not have a O2 sensor unless you get a second one.
- Finally, remember to replace the timing belt. It should be replaced every 60,000 miles but you won't know when last it was changed on your donor engine. I would also change the tensioned and the thermostat.
Good luck with your project.