For a C2 Corvette owner considering a powertrain upgrade, the choice between a rebuilt engine, a drop-in crate engine, or an LS swap is a significant one, each with its own set of trade-offs in terms of cost, reliability, and performance. Here's a detailed comparison to help you make an informed decision.

1. Rebuilt Engine

A rebuilt engine involves taking your existing C2's engine, disassembling it, cleaning and inspecting all components, and replacing only the worn-out or damaged parts. The goal is to restore the engine to factory specifications.

• Cost: This is typically the most budget-friendly option, especially if you have a shop you trust and the engine core is in good condition. The cost can vary widely based on the extent of the damage and the quality of parts used. A basic rebuild could start around $3,500, but a high-end, performance-oriented rebuild with new pistons, heads, and other components can quickly climb past $10,000.

• Reliability: The reliability of a rebuilt engine is highly dependent on the quality of the machine shop and the parts they use. A reputable shop will follow factory tolerances and use quality components, resulting in an engine that can last for many years and tens of thousands of miles. However, a "rebuilder" who cuts corners, reuses worn parts, or uses subpar materials can lead to an unreliable engine with a short lifespan.

• Performance: Performance is limited to the original engine's design. While you can add performance parts like a hotter cam, upgraded heads, and a performance intake manifold, you're still working with the C2's original small or big-block architecture. This is an excellent choice for a period-correct restoration but will not offer the power or efficiency of a modern engine.

Challenges and Regrets:

• Machine Shop Issues: Finding a trustworthy and experienced machine shop is crucial. A common regret is choosing a shop based on price alone, only to find out they have sloppy workmanship, poor communication, or a lack of attention to detail. This can lead to issues like mismatched tolerances, oil leaks, and premature component failure.

• Unforeseen Problems: A machine shop may discover more extensive damage than initially thought once they tear down the engine, such as a cracked block or worn-out crankshaft. This can significantly increase the cost and timeline of the project.

• Quality Control: Unlike a factory-produced crate engine, a rebuilt engine's quality control is entirely up to the individual shop. There is no large-scale testing process, and a short warranty (often 12 months/12,000 miles) may not cover all potential issues.

2. Drop-in Crate Engine

A crate engine is a new, pre-assembled engine that is delivered to you in a "crate." They are built to specific specifications (often with a warranty) and can be a fantastic way to get a new, reliable engine without the hassle of a rebuild.

• Cost: Crate engines can range from around $6,000 for a basic small-block to over $17,000 for a high-performance, dressed LS or big-block. This is generally more expensive than a basic rebuild but can be more cost-effective than a high-end rebuild or a full LS swap once all costs are considered.
  
  

• Reliability: This is a major selling point. Reputable manufacturers like Chevrolet Performance, Blueprint Engines, and Edelbrock have a proven track record. Their engines are built in a controlled factory environment, dyno-tested, and come with a warranty. This provides a level of quality and peace of mind that is difficult to get with a custom rebuild.
  
  

• Performance: Crate engines offer a massive range of performance options, from mild upgrades to radical, high-horsepower setups. You can choose a period-correct-looking small-block with modern internals for improved reliability or go with a fire-breathing big-block for maximum power. Many are designed to be a direct fit for the C2, minimizing installation headaches.
  
  

Challenges and Regrets:

• Ancillary Components: A common mistake is thinking the engine is the only cost. You'll likely need new accessories, a new or upgraded cooling system, and potentially a new transmission to handle the increased power. These costs can add up quickly.

• "Drop-in" is Relative: While many crate engines are designed to fit, they may not be a perfect "drop-in" solution. You might need to change motor mounts, the oil pan, or other small components to ensure proper fitment, which can be frustrating if you're not prepared.

• Warranties can be finicky: Some warranties may have strict requirements for installation or tuning. If you modify the engine or install it incorrectly, you could void the warranty.

3. LS Swap

An LS swap involves replacing the C2's original engine with a modern, fuel-injected LS-series V8. This is a popular choice for restomod projects, as it combines classic looks with modern performance, reliability, and drivability.

• Cost: This is typically the most expensive and complex option. While a used LS engine can be sourced for relatively cheap, the total cost for the swap can be high. You'll need the engine, transmission, ECM (Engine Control Module), a new wiring harness, fuel tank with an internal fuel pump, new radiator and cooling fans, headers, and countless other small parts. A complete, professional LS swap can easily cost well over $20,000, and a full restomod with an upgraded chassis can cost much more.

• Reliability: The reliability is generally excellent. LS engines are known for their durability and efficiency. They are designed to last for hundreds of thousands of miles with minimal maintenance. Fuel injection provides consistent performance in all weather and altitude conditions, something a carbureted engine cannot match.

• Performance: This is where the LS swap truly shines. The performance gain is substantial, even with a "stock" LS. The combination of high horsepower, torque, and a modern transmission (like a 4L60E or 4L80E automatic or T56 manual) transforms the driving experience. The C2 becomes a truly modern car with the capability to be a comfortable daily driver or a potent performer on the street or track.

Challenges and Regrets:

• Complexity and Fabrication: An LS swap is not a simple bolt-in affair.14 It requires significant custom fabrication, including motor mounts, transmission crossmembers, and exhaust systems.15 The wiring is complex, and integrating the modern ECM with the vintage gauges can be a major challenge.

• Hidden Costs: The little things add up. You'll need a new fuel system to handle the fuel injection, a modern cooling system, and likely new gauges or a custom gauge cluster. These costs are often overlooked by first-time swappers and are a source of regret.

• Loss of Originality: For many classic car enthusiasts, the biggest regret of an LS swap is the loss of the car's original character and value. A numbers-matching C2 is highly valuable, and an LS swap fundamentally changes the car's identity. This may not be a concern for a restomod builder, but it is a critical point for anyone focused on preservation.