New engine, what needs to be replaced?
 

I bought a new Mazda OEM 13brew engine from irperformance and swapping it to my current fd 13b engine that just blown a water seal and was wondering what I should have new for the engine swap? what is not reusable like which gasket I can still use and which one should be bought new? my car is a 2002 fd3s with a 65,000 km in the odometer in the old engine.

Any soft seals or gaskets should be replaced. Often the turbo gaskets can be reused. All coolant hoses should be changed. Contact me at the shop and I will put together a kit for you.