All the NZ new Z22SE engines had the nozzle mod done, so no recall on a NZ new one required, but Gordo is correct this was a problem with these engines
When I had my one I made sure I give it a a good engine oil flush and used good quality semi synthetic oil with a GM OEM oil filter.
These engines do use oil so don't be surprised if its burned off a litre of oil in 7k to 10k, so keep an eye on the oil level and make sure the coolant is regularly replaced
If your buying a second hand engine suggest you find out what its come out of and ensure the oil nozzle mod has been done, otherwise you could be back to square one in no time.
Plenty of info on the net about how to do this
www.z22se.co.uk easier when the engine is out of the car
An American GM designed all alloy engine,I liked it a lot.