MOPAR 1238549 Nos Connecting Rod Bearing Undersized .001

( Brand: Mopar ), ( Manufacturer Part Number: 1238549 ), ( Type: Connecting Rod Bearing ), ( Vintage Part: Yes ), ( Country Of Origin: United States )

Review MOPAR Nos Connecting Rod Bearing Pair .001 Undersized Plymouth Cyl #1238549 fits 1933-41

The **Mopar 1238549 NOS (New Old Stock) Undersized Connecting Rod Bearing (001)** is a meticulously preserved, high-performance component designed specifically for the **1933 1941 Plymouth** engine family, particularly those equipped with the iconic **389 cubic-inch inline-six powerplant**. This bearing is part of the **001 series**, which is slightly undersized to accommodate engines that have experienced minor wear or have been modified for increased compression ratios or higher RPM performance. Crafted from premium **babbitt metal**, this bearing ensures a smooth, low-friction articulation between the connecting rod and crankshaft journals, reducing heat buildup and preventing premature wear critical for maintaining peak engine efficiency and longevity. The **NOS designation** confirms that this bearing has been carefully selected from a stock of authentic, unaltered parts, free from modern rework or re-babbitting, preserving the original factory specifications and material integrity. Ideal for restoration projects, classic car enthusiasts, or performance upgrades where precision and authenticity are paramount, this bearing fits seamlessly into the original engine bay, offering a perfect balance of reliability and historical accuracy. Whether restoring a vintage Plymouth to showroom condition or fine-tuning a high-performance street rod, this **Mopar 1238549 bearing** delivers the durability and performance expected from a genuine Mopar component, ensuring your engine runs with the same smooth, resonant power it was designed to deliver over eight decades ago.

### **Pros and Cons of Buying a Mopar 1238549 NOS Connecting Rod Bearing (001 Undersized, 1933 1941 Plymouth)**

1. **New Old Stock (NOS) Condition** The bearing is unused and in original packaging, meaning it has not been installed or exposed to wear. This ensures optimal performance and longevity when installed.

2. **Undersized Option (001)** This bearing is specifically designed to be slightly smaller than the original, which can help reduce engine wear over time, especially in high-mileage or heavily used engines. It allows for a tighter fit, improving oil retention and reducing slop.

3. **OEM Quality** Mopar (Chrysler s aftermarket division) produces high-quality replacement parts that meet or exceed original specifications. These bearings are built to handle the stress of a 1933 1941 Plymouth engine.

4. **Compatibility** The part is explicitly listed for 1933 1941 Plymouth models, ensuring a proper fit without modification. This reduces the risk of installation errors.

5. **Reliability** Connecting rod bearings are critical components; using a high-quality NOS part minimizes the risk of catastrophic failure due to poor materials or manufacturing defects.

6. **Preservation of Original Engine** If restoring a classic car, using NOS parts helps maintain authenticity while ensuring reliability.

7. **Ease of Installation** Since the bearing is new, it should install smoothly without requiring excessive force or special tools beyond standard engine rebuilding procedures.

1. **Cost** NOS parts are typically more expensive than aftermarket or rebuilt alternatives. Depending on availability, this bearing may be priced higher than comparable used or remanufactured options.

2. **Limited Availability** NOS parts can be harder to find, especially for older, less common models like the 1933 1941 Plymouth. This may require sourcing from specialty suppliers, which could take time or involve shipping delays.

3. **Undersizing Considerations** While undersized bearings (001) can reduce wear, they also slightly reduce clearance. If the engine has significant internal wear (e.g., worn crankshaft journals or rod bearings), the undersized fit may not be sufficient to prevent issues like scoring or excessive heat. In extreme cases, it could lead to premature failure if the engine is already compromised.

4. **Installation Expertise Required** Proper installation of connecting rod bearings requires precision. Improper seating, oil clearance issues, or contamination can lead to failure. If the installer lacks experience, the benefits of the NOS part may be negated.

5. **Potential for Overkill** If the engine is in excellent condition with minimal wear, an undersized bearing may not offer significant advantages over a standard-fit bearing. The extra cost might not be justified unless the engine is high-mileage or heavily used.

6. **Storage and Handling Risks** Even NOS parts can degrade if not stored properly (e.g., exposure to moisture, dust, or extreme temperatures). The buyer must ensure the packaging is intact and the part is handled carefully upon receipt.

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Buying a **Mopar 1238549 NOS connecting rod bearing (001 undersized)** for a 1933 1941 Plymouth is a strong choice if you prioritize **reliability, authenticity, and long-term engine protection**. The undersized option is particularly beneficial for high-mileage or restored engines where reducing wear is critical. However, the higher cost and potential availability issues must be weighed against the benefits.

If the engine is in **good condition with minimal wear**, a standard-fit bearing might suffice, and the extra cost of the undersized NOS part could be unnecessary. Conversely, if the engine is **heavily used or being rebuilt for longevity**, the NOS undersized bearing is an excellent investment to extend its life and maintain performance.

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- You are restoring or rebuilding the engine and want the highest-quality, unused part.

- The engine has significant mileage or wear, and the undersized bearing will help reduce internal stress.

- You have access to proper installation tools and expertise (or plan to use a trusted mechanic).

- You are willing to pay the premium for NOS quality and authenticity.

- The engine is in excellent condition, and a standard-fit bearing would suffice.

- Budget is a concern, and you are open to high-quality aftermarket or remanufactured bearings (e.g., Fel-Pro, Moroso, or other reputable brands).

- You cannot confirm the engine s internal condition (e.g., crankshaft or bearing wear), making the undersized bearing less critical.

For most **restoration or high-mileage applications**, the **NOS undersized bearing is the best choice**. However, always verify the engine s condition and consult with a mechanic before installation to ensure compatibility.

Details:

Connecting Rod Bearing Pair .001 Undersized. Years 1933-1941. Plymouth: All model's. Model: All model's.

001 inch undersized. Part Type: New Old Stock. For 6-cylinder engines. Make: Plymouth.

Original Mopar parts in original packaging.

part #: 1238549 prices

• $14.95-$30.00

specifications pistonrinro:

• for makes: Plymouth, Mopar
• for years: 1933-41
• brand: Mopar
• mpn: 1238549
• type: Connecting Rod Bearing
• vintage part: Yes
• country of origin: United States

shipping pistonrinro:

• type: Fixed
• carrier: USPS
• cost: $5.00
• service: USPS Ground Advantage
• class: Standard
• transit: 3-8 Days

general pistonrinro:

• Car Truck Parts Accessories > Engines Engine Parts > Connecting Rods Parts
• condition: New other see details

returns pistonrinro:

• time: 30 Days
• policy: Returns Accepted
• paid by: Seller

seller pistonrinro:

• rating: 100.0%
• # reviews: 1653
• city: West Newbury, Massachusetts

offer pistonrinro:

• availability: In Stock
• options: Ship-to-home
• quantity: 1
• sold: 0
• started: April 29, 2026

payments pistonrinro:

• credit card: Visa
• other
• wallet: Apple-pay

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