Hey, look back a few days under Nissan Tech, there was a person asking the same question.

Make sure you blead it really well, fill up the radiator, let the thermostat open up, fill again. Run the car for a good 20~30 minutes with the bleeder screw off with the heater on.

To my personal knowledge, these are a few things that can cause the motor to over heat.

- Not bleeding coolant system properly
- Faulty parts, such as the parts you have installed, but also include clutch fan
- Minor head gasket leak
- Hmmm, there a few more things, but I am too tired to think right now.

Again, look back at that thread, there's a lot of suggestions on there.