* Size and Weight: The 454 is massively larger and heavier than the Fiero's original engine. This creates enormous challenges with regards to:
* Engine Bay: The Fiero's engine bay is incredibly small. You'll need to fabricate custom engine mounts, significantly modify or completely replace the firewall, and likely cut away substantial portions of the body structure to accommodate the engine's dimensions.
* Weight Distribution: The added weight drastically alters the Fiero's center of gravity, severely impacting handling and potentially making it unsafe. Reinforcement of the chassis will be crucial.
* Exhaust: Routing the exhaust system will be incredibly difficult given the limited space. Custom headers and exhaust fabrication are essential.
* Transmission and Drivetrain:
* Transmission Compatibility: You'll need a transmission capable of handling the 454's torque. A strong automatic transmission (like a TH400 or 700R4) or a manual would be necessary, and again, custom mounts and potentially a custom driveshaft would be required to connect it to the Fiero's rear axle or a modified rear end. The Fiero's original rear end is likely insufficient for the 454's power.
* Rear Axle: The Fiero's stock rear axle is not designed for the torque and power of a 454, making it prone to failure. Upgrading to a stronger, possibly custom-built, rear end assembly is mandatory.
* Cooling: The 454 generates significantly more heat than the Fiero's original engine. A substantial custom cooling system – likely including a large radiator, upgraded cooling fans, and possibly an auxiliary electric fan – is needed to prevent overheating.
* Other Considerations:
* Electrical System: You'll probably need to upgrade the Fiero's electrical system to handle the demands of the larger engine.
* Fuel System: A high-capacity fuel pump and fuel lines are necessary to supply enough fuel to the 454.
* Brakes: Upgrading the braking system is crucial to safely handle the increased power and weight.
In short: This is a project for experienced fabricators and engine mechanics with access to specialized tools and equipment. It's not a weekend project; it's a long-term, potentially very expensive endeavor. Consider the immense amount of custom work, the significant safety risks if not done properly, and the sheer difficulty of the task before attempting it. Many people attempt similar swaps and abandon the project due to the complexities involved.
