Thermostat woes in 2G

[baldur]

Now, I have a 2G GSX and it's temperatures are all over the place, it's not overheating but when it idles or I'm driving in slow traffic the gauge shows around 215 degrees (around the temp where the fans will come on with a stock ECU) and when I'm driving 60mph on the highway it's a steady about 190 degrees or so.
Now, I find it a bit unusual that this car has the thermostat on the cold water inlet rather than on the hot water outlet, and I've seen pictures that indicate that the first gen cars didn't have such an oddball thermostat setup.
I have a standard 180 degree thermostat but since the thermostat is located in the cold water, that'd indicate that I'd need a thermostat several degrees colder than the desired operating temperature, correct?
I did notice that there is a bypass in the bottom of the thermostat housing with a spring on it, but I don't know how much coolant is actually flowing through that when the engine is at operating temperature, the spring is pretty damn stiff.

Question is, what year did they change the thermostat location? Are the thermostat housings interchangable between 1G and 2G? Does the 1G have a more stable operating temperature?

 

[Defiant]

Something's up. The thermostat lives in the top of the head. If yours is running cool at speed, it's not closing as it should.
Are you chasing after the oil thermostat?

 

[baldur]

The car has no oil thermostat and the oil cooler has been swapped out for an air cooled unit because the 3" downpipe didn't clear the stock oil cooler+filter. The oil cooler coolant lines are plugged.
It also has an oilcooled turbo so the coolant lines that formerly connected to the turbo are now just bypassed.
I think I'm going to just keep the thermostat like it is but set the fans to come on at a lower temp.