* The condition of the 3400 engine: A used engine will be significantly cheaper than a rebuilt or new one. A junkyard pull could be the cheapest option, but carries the most risk. A professionally rebuilt engine will be the most expensive.
* Parts needed beyond the engine: You'll need more than just the engine. This includes:
* Transmission: Will your existing transmission work? Likely not without modification. A compatible transmission will add significant cost.
* Wiring harness: The 3400's wiring will likely be different from the Cavalier's. You may need a custom harness or significant modification.
* Engine mounts: The 3400 engine likely won't fit directly into the Cavalier's engine bay without custom mounts.
* Exhaust system: The exhaust will likely need to be modified or replaced.
* Cooling system: The radiator and hoses may need to be upgraded or adapted.
* Computer/ECU: You'll probably need a compatible ECU, or have your existing one reprogrammed.
* Labor costs: This is a significant expense. Unless you're very mechanically inclined and have the tools, you'll need a mechanic, and their rates vary widely by location and experience. This swap is a complex project.
* Additional unforeseen issues: During the swap, you might uncover other problems that require additional parts or labor.
Rough Estimate:
Considering all the factors, a *reasonable* estimate for a complete 3400 swap, including a used engine and professional labor, would likely range from $3,000 to $8,000 or more. The lower end assumes you find a very cheap used engine and do some of the simpler work yourself. The higher end reflects the use of a professionally rebuilt engine, custom fabrication, and substantial labor costs.
Recommendation:
Before undertaking this project, thoroughly research the swap specifics for your particular year and model of Cavalier Z24. Look for forums and online communities dedicated to Cavalier modifications. This will give you a better understanding of the challenges and potential costs involved. Consider whether the cost and complexity are justified compared to other performance upgrades or purchasing a different car altogether.
