Mine is water-cooled. I'm not sure if it was from the factory. My car was born in 9/83. The retro kit consists of a different thermostat housing, lower heater return line, water lines to/from turbo, and banjo fittings. When I removed my turbo, I ended up screwing my water lines completely up. Instead of buying a new kit from Nissan for about $600, I ordered some braided, stainless-steel house from Summit Racing. Cost me $140 but is removable with ease and looks about 20 times cooler.
The J-Spec E15 had a different intake manifold. It used a side mounted TB like a modern GA or SR motor. The exhaust manifold kinda looks like a later model ('87) manifold with a turbo flange on it. The Aussies call it the mid-mount manifold. The US (Aussie unleaded) manifold came as that close coupled, high-mount piece of crap (You know what I'm talking about). In Australia, they also had a leaded E15ET that used a low-mount manifold that more closely resembled our high-mount manifold. I beleive the J-Spec E15 made about 110HP but I'm not completely sure. As far as water cooling or boost, I have absolutely now idea.
