OLDSMOBILE 371870 Ci Power Heads

( Manufacturer Part Number: 371870 ), ( Type: Cylinder Head ), ( Material: Cast Iron ), ( California Prop 65 Warning: Unk ), ( Performance Part: Yes )

Review OLDSMOBILE 371 Ci Tri Power Heads fits J2 1957–1958

The **Oldsmobile 371870 1957 1958 J2 371 CI Power Heads** represent a legendary and highly sought-after component in the world of classic American muscle car restoration and performance tuning. These cast-iron cylinder heads, originally designed for Oldsmobile s iconic **372-cubic-inch Rocket V8**, are a cornerstone of the brand s mid-century engineering legacy, embodying a perfect blend of durability, simplicity, and raw power. Engineered for the **1957 1958 J2 series** (including models like the Dynamic 88, Starfire, and 98), these heads were built to withstand the demands of high-performance driving while maintaining reliability a hallmark of Oldsmobile s early V8 dominance. The **371870 designation** specifically refers to the **CI (cast-iron) version** of the heads, which feature a robust, time-tested design with **four-valve-per-cylinder** architecture, **1.94-inch intake and exhaust valves**, and **1.60-inch rocker arms**, all optimized for smooth airflow and efficient combustion. The **371 CI heads** are particularly prized for their **mechanical simplicity**, lacking the complexity of later aluminum or high-performance variants, making them ideal for restorers seeking an authentic, no-frills approach to building a period-correct powerplant. Their **flat-top combustion chambers** and **integrated valve springs** contribute to a classic, no-nonsense performance profile, while the **cast-iron construction** ensures longevity, even under heavy loads. Whether paired with a **372 Rocket V8** for a faithful reproduction of a 1957 58 Oldsmobile s legendary power delivery or modified for modern high-performance applications, these heads offer a unique opportunity to channel the spirit of an era when American engineering redefined automotive excellence. For enthusiasts and mechanics alike, the **371870 371 CI Power Heads** are not just components they are a tangible piece of automotive history, embodying the raw, unfiltered power that defined the golden age of the V8.

### **Pros and Cons of Buying a 1957 1958 Oldsmobile J2 371 CI Power Head Engine**

#### **Pros**

The **Oldsmobile 371 CI Power Head** (introduced in 1957) is a classic American V8 engine known for its durability, character, and historical significance. Here are its key advantages:

1. **Strong and Reliable Base Engine**

- The **371 CI** (Cubic Inch) engine was a refinement of the earlier **372 Rocket V8**, featuring a **cast-iron block and head**, which made it more robust than some aluminum-block contemporaries.

- It was designed for **high torque** (around **300 350 lb-ft** in stock form) and could handle heavy loads, making it suitable for classic cruising, drag racing, or street use with modifications.

- The **pushrod design** is simpler and more forgiving than modern overhead-cam engines, making it easier to maintain and modify.

2. **Proven Durability**

- Many **371 CI engines** from this era have lasted **decades** with proper maintenance, especially when used in **high-mileage applications** (e.g., taxis, delivery trucks, or daily drivers).

- The **cast-iron construction** resists warping better than some aluminum blocks, though it is heavier.

- **Big-block architecture** allows for **easy upgrades** (larger valves, forged internals, high-performance camshafts, and even **turbocharging** in later years).

3. **Classic American Sound and Presence**

- The **deep, throaty growl** of a **371 CI** is iconic in classic American muscle cars, making it a **great choice for enthusiasts** who appreciate the **vintage V8 experience**.

- The engine fits well in **restomod projects**, **hot rods**, or **street rods**, adding authenticity to a build.

4. **Modification Potential**

- **Easy to work on** many parts are still available from aftermarket suppliers (e.g., **Edelbrock, Holley, Crane, and Summit Racing**).

- **Big-block swaps** are common, meaning you can **replace it with a more modern (but still classic) engine** like a **350 Chevy, 400 Ford, or even a modern LS-based big block** if needed.

- **Fuel injection upgrades** (like **Holley EFI or Mega Squirt**) can modernize fueling while keeping the **mechanical simplicity** of the pushrod design.

- **Turbocharging** was later adopted (especially in **1958 1960 models**), allowing for **serious power gains** with the right modifications.

5. **Affordability of Parts and Labor**

- **Used parts** (blocks, heads, cranks, rods, etc.) are **relatively cheap** compared to modern big blocks.

- **Labor costs** for basic maintenance (valve adjustments, timing chain replacement, etc.) are **lower than on newer engines** due to simpler design.

- **Restoration projects** can be **budget-friendly** if you source parts from junkyards or online marketplaces.

6. **Historical Significance**

- The **371 CI** was part of Oldsmobile s **transition from Rocket V8 to Rocket V8 Rocket** (with fuel injection in 1957), making it a **key engine in GM s evolution**.

- Owning one allows you to **drive a piece of automotive history**, which is appealing to collectors and enthusiasts.

---

#### **Cons**

While the **371 CI Power Head** has many strengths, it also comes with **significant drawbacks** that must be considered before purchase.

1. **Poor Fuel Economy**

- Even in stock form, the **371 CI** drinks **gasoline like a thirsty beast** expect **around 10 15 MPG** in a stock or lightly modified car.

- **Modern fuel injection and turbocharging** can improve efficiency, but **carbureted versions** will always be **gas-guzzlers**.

2. **High Maintenance Requirements**

- **Valve adjustments** are **manual and frequent** (every **6,000 8,000 miles** in stock form, less with performance cams).

- **Timing chain and tensioner wear** is common, requiring **regular inspection and replacement** (often **every 50,000 100,000 miles**).

- **Rod bearings and main bearings** can wear out if the engine is **overworked or neglected**, leading to **expensive repairs**.

- **Head gasket failures** are a **known issue**, especially in **high-mileage or overheated engines**. **Silica-based coolants** and **proper head gasket replacement** (with **copper or modern gaskets**) are essential.

3. **Weaknesses in Original Design**

- **Cast-iron heads** are **heavy and prone to warping** if overheated, leading to **leaking valves and poor sealing**.

- **Stock cylinder heads** have **small ports and valves**, limiting **airflow** a major bottleneck for **high-performance builds**.

- **Stock carburetors (like the Rochester 4BC or 4V)** are **notoriously finicky**, requiring **constant tuning** for smooth operation.

- **Stock oil pumps** are **weak**, leading to **oil starvation** under high RPM or heavy loads **upgrading to a **Crane or Moroso oil pump** is recommended**.

4. **Emissions and Modern Compliance Issues**

- **Stock 371 CI engines are not EPA-compliant** for modern use in many states.

- **Smog checks** can be **difficult or impossible** without **major modifications** (like **catalytic converters, EGR deletions, or fuel injection upgrades**).

- **Running a carbureted engine** in some areas may **violate emissions laws**, forcing owners to **convert to fuel injection** or **register the car as a "classic" with exemptions**.

5. **Rust and Structural Issues in Older Cars**

- Many **1957 1958 Oldsmobiles** suffer from **frame rust**, **body corrosion**, and **weak suspension components**.

- **Original wiring harnesses** are **prone to failure**, requiring **restoration or replacement**.

- **Stock transmissions (like the **Turbo-Hydramatic 350**) are **notoriously weak** and often need **rebuilding or replacement**.

6. **Limited Aftermarket Support Compared to Chevy/Ford**

- While **parts exist**, they are **not as widely available** as for **Chevy 350/454** or **Ford 390/428** engines.

- **Performance parts** (like **high-flow heads, forged internals, or supercharger kits**) are **less common**, making **serious modifications more expensive**.

- **Tuning and diagnostics** can be **more challenging** without a **large community of builders** like with Chevy or Ford big blocks.

7. **High Cost of Restoration**

- **Full restorations** (engine, transmission, suspension, body, interior) can **easily exceed $10,000 $20,000 **, depending on the car s condition.

- **Finding a complete, drivable example** is **rare** most require **major work**, which can be **time-consuming and costly**.

8. **Driving Experience Limitations**

- **Stock handling is poor** **1957 1958 Oldsmobiles** were **heavy, understeer-prone, and slow** by modern standards.

- **Modern safety features (ABS, airbags, stability control) are absent**, making them **less safe in a collision**.

- **Noise and vibration** can be **annoying** in some cases, especially if the **mounting system is worn** or the **engine is not balanced**.

---

### **Ending Conclusion**

The **Oldsmobile 371 CI Power Head** is a **fantastic engine for the right owner** someone who **appreciates classic American muscle, enjoys mechanical work, and doesn t mind trade-offs** for the sake of **driving history**. It is **durable, modifiable, and full of character**, making it a **great choice for enthusiasts** who want to **build a restomod, hot rod, or street machine**.

- **Daily drivers** (due to **poor fuel economy, high maintenance, and emissions issues**).

- **Budget-conscious buyers** (restoration costs can be **high**).

- **Those who want modern convenience** (no power steering, no air conditioning, poor safety).

- **People who prefer easier-to-find parts** (Chevy/Ford big blocks have **better aftermarket support**).

If you **love classic cars, enjoy working on engines, and want a project with big rewards**, the **371 CI is an excellent choice**. If you **prioritize modern comfort, reliability, or low maintenance**, you may want to consider **alternative engines** (like a **restored Chevy 350, Ford

Details:

Made from durable cast iron, these heads are considered performance parts for car enthusiasts looking to enhance the power and efficiency of their vehicles. The product is a pair of vintage 1957 1958 Oldsmobile J2 371 ci tri power cylinder heads, specifically designed for the left and right sides engine.

part #: 371870 price

• $750.00

specifications cylinderheapar:

• for models: J2
• for makes: Oldsmobile
• for years: 1957-1958
• mpn: 371870
• type: Cylinder Head
• material: Cast Iron
• california prop 65 warning: Unk
• performance part: Yes

payments cylinderheapar:

• other
• credit card: Diners-club
• wallet: Apple-pay
• cash

seller cylinderheapar:

• # reviews: 5120
• rating: 100.0%
• city: Inverness, Florida

returns cylinderheapar:

• policy: No Returns

shipping cylinderheapar:

offer cylinderheapar:

• quantity: 1
• sold: 0
• best offers: True
• options: Seller-arranged-local-pickup
• started: June 11, 2026
• availability: In Stock

general cylinderheapar:

• condition: Used
• Car Truck Parts Accessories > Engines Engine Parts > Cylinder Heads

Oldsmobile 371870 Is Similar To:

• 567322 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 Oldsmobile V8 Cylinder Heads Olds 303 324 371 Engines 1950s Hot Rat Rod (25.9% similar) He recently passed away and these heads were bought out of the estate. This is a very nice pair of core heads that are ready to be rebuilt. These heads have no porting or modifications I can see. Don't miss out. There are also no cracks or repairs. A couple chambers have some pitting as shown. This ...(December 1st, 2016)
• Complete 425 Miles Toronado 1966l 455 442 Valvetrain Oldsmobile Lo Heads 1967 (28.4% similar) Ready to run. Rebuilt motor,as removed,complete valve train including rocker arms and bridges...(May 11th, 2015)
• 389395 Oldsmobile Olds Super Rocket Big Valve Cylinder Heads (44.4% similar) Listing is for ' 66' oldsmobile 425CI super rocket big valve b cylinder heads. The heads are being sold as cores. Intake valves measure head part number early cam bank angle of 45 degrees stamp on right side cylinder N519819 came off a running 425 big block motor that I parted out years ago. Free ...(July 24th, 2018)
• 394487 2 High Compression Oldsmobile 4 330 Cylinder Heads 350 403 Welded Olds (37.3% similar) The ports and bowls need to be cleaned up, I got the heads for the springs, retainers and keepers. With modifications these heads will work on the olds 403. Comparing these to a stock pair of 3 heads I have, these look to have been surfaced by. Selling a pair of bare high compression wag cylinder ...(March 31st, 2016)
• 397363 Oldsmobile Pair Big Block Heads (40% similar) Selling pair of used oldsmobile big block c heads. Don't know much about them other than they were on a late 60S oldsmobile 455...(March 29th, 2018)
• B1368767 B Oldsmobile Fire Cylinder Heads Set (45.1% similar) Shipping estimate is for 1 head. Light surface rust needs to be cleaned. Looks worst in pics than real life. I m selling extra parts removed from a 1965 oldsmobile cutlass F85 4-DOOR, 225 V6, automatic transmission, a-body car. A set of heads off V-6 dauntless odd fire motor. Very little to no ...(March 31st, 2018)
• 394548 Gm 1967 68 69 Oldsmobile 442 C Heads Big Valve Wd30 425ci 455ci Motors (32.8% similar) These have the 80CC chambers, the valves are the big on the exhaust ports, the wall was length need to the outer surface of the head to increase power and also works better with headers. That was the only modifications done to these heads. Many people believe these are the best flowing big block ...(July 12th, 2016)
• 403859 Oldsmobile 1970 Cutlass F85 Sb W31 350 6 Cylinder Heads Pair Small Block (50% similar) Includes valve covers. Shipping should be between ask all questions prior to buying. You are buying on a pair of 70 olds 6 heads just removed from a 70 cutlass. Motor had been sitting since mid 80S. These are for a small block oldsmobile engine. Heads are sold as a core for rebuild. These have the ...(August 16th, 2016)
• Cfd-411-929 Oldsmobile Cylinder Heads Rocket 350 73 Part Code 8 (38.3% similar) I will answer your questions as best as I can. They are for a 1973 oldsmobile. The shipping cost would be expensive because the heads are very heavy. For your consideration. The headers are still in decent shape. A pair of vintage rocket 350 cylinder heads. The best advice would be to drive here ...(September 20th, 2016)
• 571870 Oldsmobile Rocket J2 Rare 1958 371 Pair Cylinder Heads 16 Is A Ci (49.6% similar) For sale is a pair of rare 1958 oldsmobile 371 cylinder heads j2 16 is a ci. They both appear in good shape they were removed for a block build as I found the complete motor un assembled with no block but everything else I have...(August 15th, 2016)
• 403686 Oldsmobile Heads Olds Big Block Reconditioned Cutlass (29.1% similar) Can be used for hydraulic or solid camshaft. Condition is fully remanufactured. Up for bid is a really nice pair of matched cylinder heads from my oldsmobile. Exhaust ports cleaned up, all new Manley valves, seals, springs, locks, keepers, studs and guide plates. 1 pair heads left and right 1970 ...(September 11th, 2020)