thermostat replacement

Follow the upper hose to the engine, then follow the next hose down to where it connects. That is where the thermostat is.

Check out this site http://www.300zx-twinturbo.com/cgi-bin/manual.cgi It is an online repair manual for the 300zx. Check out section "Engine Lub and Cooling.." page 11. It will show you step-by-step how to replace.

it is located behind a couple of belt housings and something else with a gasket that I really dont want to touch unless I have to.