Here's why:
* Substantial Engineering Required: The SRT-4 engine is a front-wheel-drive, turbocharged 2.4L inline-4. The New Yorker Fifth Avenue is a rear-wheel-drive car with a much larger engine bay designed for a V6. Adapting the SRT-4's engine mounts, transmission, drivetrain, and supporting systems (wiring, computer, etc.) to the New Yorker's chassis would require extensive fabrication and custom engineering. It's not a bolt-in swap.
* Transmission Incompatibility: The SRT-4 uses a front-wheel-drive transmission, while the New Yorker is rear-wheel-drive. This means you'd need a completely new transmission and a custom driveshaft setup.
* Computer and Wiring: The SRT-4's engine management system is vastly different from the New Yorker's. Integrating the SRT-4's computer and wiring harness into the New Yorker's electrical system would be a major undertaking requiring specialized knowledge and potentially custom wiring.
* Cost Prohibitive: The cost of parts, fabrication, and labor involved in such a project would far exceed the value of the New Yorker Fifth Avenue. It would likely be cheaper and easier to buy a car already equipped with an SRT-4 engine.
While theoretically possible with immense effort and resources, it's simply not practical or feasible for a typical car enthusiast.