While you could theoretically fit a massive engine with enough custom fabrication (cutting and welding the firewall, modifying the subframe, etc.), a more practical approach focuses on engines that require less extensive modifications. Popular swaps often include LS-series engines (like the LS1, LS2, LS3, or LS6) from later-model GM vehicles. These are relatively common, offer good performance, and require less radical changes than some other choices.
You'll face challenges regardless of the engine choice, including:
* Engine mounts: You'll need custom engine mounts to fit the new engine.
* Transmission: You'll likely need a new transmission and associated components that are compatible with the chosen engine.
* Wiring harness: Adapting the wiring harness to work with the new engine is crucial.
* Exhaust system: A custom exhaust system will be needed.
* Driveshaft: The driveshaft length will likely need adjusting.
* Computer/ECU: You'll likely need a stand-alone engine management system or a modified stock system to run the new engine.
In short, there's no easy answer. The "biggest" engine is limited more by practicality and the cost/effort of modifying the car than by any inherent physical limitation of the chassis itself. Focus on a swap that balances power with the amount of custom fabrication required. LS-series engines are a good starting point for many reasons.
