* Massive Modifications: The AOD transmission is completely different from a manual transmission in terms of its mounting points, driveshaft length, clutch mechanism, pedal assembly, and related linkages. You'd essentially need to fabricate a significant portion of the transmission tunnel, modify the engine's bellhousing (or find a compatible one), custom-build a driveshaft, install a clutch pedal assembly, and re-route hydraulic lines, among countless other alterations.
* Computer Control Issues: The 1987 Town Car's engine management system (ECU) is designed to work with an automatic transmission. A manual transmission requires a different strategy for controlling the engine, and significant rewiring and potentially a custom ECU setup would be required.
* Cost-Effectiveness: The cost of all the parts, fabrication work, custom machining, and specialized labor would far exceed the value of the car, especially considering that most people wouldn't want to invest in such a project.
* Engineering Challenges: This is not a simple bolt-on swap. A high level of mechanical engineering and fabrication skills is needed. Getting it to function correctly, and safely, would require extensive testing and fine-tuning.
In short, while technically *maybe* possible with an enormous amount of time, money, and expertise, it's not a practical or worthwhile project for a 1987 Lincoln Town Car. It would be far easier and cheaper to find a car that already has the manual transmission you desire.
