Rebuilding the 400:
* Pros:
* Potentially cheaper: If you have the tools and mechanical skills, rebuilding can be significantly cheaper than buying a crate engine. You can also tailor the rebuild to your specific needs and budget.
* More power potential: A properly rebuilt 400 can produce more torque than a stock 350. You can also customize it for even more power.
* Sentimental value: If it's an engine from a cherished vehicle, rebuilding maintains originality.
* Cons:
* Time-consuming: A complete rebuild is a labor-intensive project.
* Requires specialized tools and skills: Lacking these will increase costs (renting tools, hiring a mechanic) and potentially lead to mistakes.
* Parts availability: Finding parts for a 400, especially high-performance parts, might be more difficult and expensive than for the more common 350.
* Unknown condition: You might discover hidden problems during the disassembly that significantly increase the cost and time.
Buying a 350 crate engine:
* Pros:
* Faster and easier: Installation is relatively quick compared to a rebuild.
* Guaranteed performance: Crate engines come with warranties, providing peace of mind.
* Readily available parts: Parts are abundant and easily accessible.
* Predictable cost: The price is upfront and known.
* Cons:
* More expensive: Crate engines are significantly more costly than a rebuild.
* Less power (potentially): A stock 350 will likely produce less torque than a properly built 400.
* Less customization: Modifying a crate engine to significantly increase power might negate the advantages of buying it pre-built.
To help you decide, consider these questions:
* What's your budget? Get quotes for both a 400 rebuild (including parts and potential machining) and a 350 crate engine.
* What's your mechanical skill level? Are you comfortable disassembling, inspecting, machining, and assembling an engine?
* What's your time constraint? How long are you willing to spend on the project?
* What performance goals do you have? Do you need more torque, horsepower, or just reliable operation?
* What's the condition of the 400? Has it been neglected? Are there any obvious problems? A compression test is essential.
In short: If you're on a tight budget, have the skills and time, and want potentially more power, rebuilding the 400 might be worth it. If you value convenience, reliability, and a guaranteed product, a 350 crate engine is the easier, albeit more expensive, route. A thorough cost analysis considering both labor and parts is crucial before making a final decision.
