Hey man. SR20ve B13 gave you some excellent advice... I would just take the wiring loose from the ECU and pull it through the firewall. Then drop everything out the bottom in one piece. It is the easiest and this is how nissan does it from the factory. Also instead of using adapters for the coolant hoses look at Andreas Mikos thread titled. A Hose To Remember for the VVL.
Any other questions pm me.
Any other questions pm me.