1. Pistons, Rings, Rods & Parts Engines Components For Sale
  2. sku: 12245065747131861
  3. JOHNSON NH-840M

JOHNSON Rod Bearing Set American 287

fits model: Nh-840m, X2, 250, 327. make: Amc, Johnson. year: 1956-66.

Johnson Nh-840m X2 Rod Bearing Set 1956-66 American Motors Amc 250 287 327

( Brand: Johnson ), ( Manufacturer Part Number: NH-840M ), ( Type: Connecting Rod Bearing ), ( Country Of Origin: United States ), ( Vintage Part: Yes )

Review JOHNSON Rod Bearing Set American Motors Amc 287 fits NH-840M X2 250 327 1956-66

The **Johnson NH-840M x2 Rod Bearing Set** is a meticulously engineered aftermarket upgrade designed to enhance the performance, durability, and reliability of the iconic **1956 1966 American AMC V8 engines**, including the legendary **250, 287, and 327 cubic inch powerplants**. Crafted from high-grade, precision-machined steel, these **double-row ball bearings** are engineered to replace the stock rod bearings, offering superior load-bearing capacity, reduced friction, and improved oil flow critical factors for engines that demand both brute strength and longevity. Unlike generic aftermarket alternatives, the NH-840M bearings feature a **hardened steel cage and precision-ground raceways**, ensuring smoother operation under high RPMs and heavy loads, whether you re hauling heavy payloads, towing, or pushing the engine to its limits on the drag strip. The **interchangeable design** makes installation straightforward, requiring only basic tools and a bit of patience, while the **sealed construction** minimizes the risk of contamination from debris or oil sludge, a common issue in high-mileage or heavily modified engines. Whether you re restoring a classic muscle car, building a high-performance street rod, or simply looking to extend the life of your AMC V8, these bearings deliver a **noticeable improvement in rod journal stability**, reducing the risk of catastrophic failure while allowing the engine to breathe easier under stress. Built to meet or exceed OEM specifications, the NH-840M set is a **proven choice** among enthusiasts and mechanics alike, offering a balance of strength, precision, and ease of installation that makes it a standout upgrade for any AMC V8 owner seeking reliability without sacrificing performance.

### **Pros and Cons of Buying a Johnson NH-840M X2 Rod Bearing Set for 1956 1966 AMC 250/287/327 Engines**

#### **Pros:**

1. **High-Quality Material** The NH-840M bearings are made from high-grade steel with a precision-machined surface, ensuring durability and smooth operation under heavy loads.

2. **Proven Performance** Johnson bearings are widely trusted in the automotive aftermarket, especially for muscle cars and performance applications, offering reliable support for high-RPM and high-torque conditions.

3. **Easy Installation** The X2 rod bearing set is designed for straightforward installation, requiring minimal special tools. The bearings are pre-lubricated and come with proper shims for proper fitment.

4. **Compatibility** Specifically engineered for AMC 250, 287, and 327 engines from 1956 to 1966, ensuring a perfect fit without modification.

5. **Reduced Wear and Noise** Proper rod bearings minimize friction, reducing engine wear and preventing the metallic clanking noise associated with worn-out bearings.

6. **Cost-Effective Upgrade** Compared to full engine rebuilds or high-end aftermarket bearings, this set provides a budget-friendly way to restore engine reliability.

7. **Warranty Coverage** Johnson bearings typically come with a manufacturer s warranty, offering some protection against defects in materials or workmanship.

#### **Cons:**

1. **Limited Availability** As a specialized part for older AMC engines, sourcing may require searching through niche suppliers, eBay, or specialty auto shops, which could lead to higher shipping costs or delays.

2. **Price Sensitivity** While not extremely expensive, the cost may be a concern for budget-conscious buyers, especially if other engine components (like pistons or crankshafts) are also worn.

3. **Installation Skill Required** Though straightforward, improper installation (e.g., incorrect shimming, cross-threading, or improper torque) can lead to premature failure. DIYers without experience may need professional help.

4. **No Performance Boost** This is a maintenance/repair part, not a performance upgrade. It restores reliability but won t increase horsepower or torque.

5. **Potential for Counterfeit Parts** Since these are older-model parts, there s a risk of purchasing knockoffs or low-quality replicas, so buying from reputable sellers is critical.

6. **Additional Maintenance Needed** Replacing rod bearings often requires removing the engine from the vehicle, which may necessitate other related services (e.g., timing belt/replacement, valve cover gasket, or oil pan gasket).

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### **Conclusion**

The **Johnson NH-840M X2 rod bearing set** is a solid choice for restoring the health of a 1956 1966 AMC 250/287/327 engine. It offers a balance of quality, ease of installation, and compatibility while addressing critical wear issues that could lead to catastrophic engine failure. However, the decision to purchase should consider factors like availability, installation confidence, and whether this is part of a broader engine rebuild or just a targeted repair.

If your engine is showing signs of rod bearing wear (e.g., oil consumption, knocking, or blue smoke), this set is a **practical and cost-effective solution** to prevent further damage. For those without mechanical experience, consulting a trusted mechanic may be wise to ensure proper installation.

### **Recommendation**

**Buy the Johnson NH-840M X2 rod bearing set if:**

- Your AMC engine exhibits symptoms of rod bearing failure (knocking, oil leaks, or excessive wear).

- You re comfortable with basic engine disassembly or have access to a mechanic for installation.

- You want a reliable, high-quality part that extends engine life without overcomplicating the repair.

**Avoid purchasing if:**

- You re unsure about the engine s condition and need a full diagnostic before committing.

- You re on a tight budget and cannot afford the time or labor for installation.

- You suspect other major engine components (e.g., crankshaft, pistons) are also failing, which would require a more comprehensive rebuild.

For long-term reliability, pair this repair with regular oil changes, proper lubrication, and monitoring for future wear. If the engine is part of a classic or high-mileage vehicle, consider upgrading to aftermarket bearings with enhanced coatings (e.g., molybdenum or ceramic) for added protection.

Details:

Size: .002 Undersized X2. Condition: NORS New Old Replacement Stock. A Note on Fitment Accuracy: We manually research and cross-reference our fitment data using vintage manufacturer catalogs. This set provides factory-correct fitment for the 250, 287, and 327 cubic inch displacements used across AMC, Nash, Hudson model's between 1956 1966.

Engine Fitment: AMC V8 250, 287, 327 CID. Unbeatable Prices Expectations: While many of our vintage parts were manufactured decades ago, they remain unused and high-quality. These slight aesthetic differences are a result of historical production processes and do not impact the parts integrity, performance, or authenticity. These bearings are vital for restoring proper crankshaft protection and maintaining reliable oil pressure in iconic muscle cars luxury cruisers like the AMC Ambassador, Rambler Rebel, final series Hudson Hornets.

Part Number: NH-840M. Some original boxes may show signs of shelf-wear, such as dust, tape, or surface distress from years storage. Position: Connecting Rod Bearings. Key Features:: Brand: Johnson.

part #: nh840m prices

  • $43.95-$359.00

specifications pistonrinro:

  • for models: Nh-840m, X2, 250, 327
  • for makes: Amc, Johnson
  • for years: 1956-66
  • brand: Johnson
  • mpn: Nh-840m
  • type: Connecting Rod Bearing
  • country of origin: United States
  • vintage part: Yes

general pistonrinro:

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

returns pistonrinro:

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

offer pistonrinro:

  • started: February 3, 2026
  • availability: In Stock
  • quantity: 1
  • sold: 0
  • options: Ship-to-home

seller pistonrinro:

  • city: Lewiston, Idaho
  • rating: 99.8%
  • # reviews: 15973

payments pistonrinro:

  • other
  • credit card: Mastercard
  • wallet: Paypal

shipping pistonrinro:

  • type: Calculated
  • cost: $8.52
  • transit: 3-8 Days
  • service: USPS Ground Advantage, USPS Priority Mail
  • class: Standard, Expedited
  • carrier: USPS
for models: nh-840m, x2, 250, 327, for makes: amc, johnson, for years: 1956-66, type: connecting rod bearing, country of origin: united states, vintage part: yes,
category: auto parts > car truck parts accessories > engines engine parts > connecting rods parts, sku: 12245065747131861,
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  • New other (see details). Offer #1 priced at $43.95 + $9.13 shipping estimate = $53.08* total. +$9.13 shipping
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