To use the later style oil cooler adapt you need to (obviously) replace the oil cooler adapter (actually all you need is the extension) and the two steel tube whcih connect to the front of the engine, and the turbocharger oil drain tube. It is a little tricky replacing the steel tubes where they pass under the motor mount, but it can be done in the car. My wife's 1986 used to be just like your 1985 until I converted it. The parts are not expensive, used. The worst part of the job is all of the accumulated grime from over 15 years of servidce. Finding the turbo oil drain tube in the UU-Pull It salvage yard is tough, since those are usually pulled with the turbo.