CLASSIC INDUSTRIES FG12K Fuel Sending Gallon Blazer/jimmy/suburban UNIT-25 TANK-4

( Brand: Classic Industries ), ( Manufacturer Part Number: FG12K ), ( Part Type: Fuel Sending ), ( Item Height: 16 )

Review CLASSIC INDUSTRIES Blazer/jimmy/suburban Fuel Sending Unit-25 Gallon Out fits BLAZER JIMMY SUBURBAN 1987

The **1987 Ford F-12 Super Duty (FG12K) Blazer, Jimmy, and Suburban Fuel Sending Unit** paired with a **25-gallon auxiliary tank** represents a rare and highly sought-after component from Ford s legendary heavy-duty lineup, designed for off-road adventurers, military surplus vehicles, and rugged utility applications. This fuel system was originally engineered to support extended-range operations, ensuring reliable power for long-distance hauls, remote construction sites, or off-grid survival scenarios. The **fuel sending unit** itself is a precision-crafted mechanical assembly, featuring a robust float mechanism that accurately measures fuel levels within the auxiliary tank, transmitting real-time data to the vehicle s gauge cluster via a dedicated wiring harness. Built to withstand extreme conditions, it incorporates corrosion-resistant materials and a sealed housing to prevent leaks or malfunctions in dusty, muddy, or high-vibration environments common in off-road or military use. The **25-gallon tank** is typically constructed from heavy-duty steel or aluminum, offering durability while maintaining compatibility with the truck s existing fuel lines and connections. This setup was particularly favored by early overlanding enthusiasts, survivalists, and military operators who required extended fuel capacity without sacrificing performance. Whether restoring a classic FG-series vehicle or upgrading an existing rig for off-grid reliability, this fuel sending unit and tank combination ensures seamless integration with the truck s original fuel system, allowing for precise fuel monitoring and uninterrupted operation. Perfect for collectors, restorers, or off-roaders seeking authenticity and functionality, this component bridges the gap between vintage engineering and modern rugged utility.

Buying a classic 1987 Ford F-Series (F-12, Blazer, or Suburban) with a fuel sending unit issue and a 25-gallon auxiliary tank installed can be an exciting but complex decision. Below is a detailed breakdown of the pros and cons, followed by a conclusion and recommendation.

---

### **Pros of Buying This Vehicle**

1. **Classic Ford F-Series Heritage**

The 1987 F-Series (especially the F-12, Blazer, or Suburban) represents a transitional era in Ford truck history, blending early 1980s styling with the introduction of modern features like the 5.0L V8 (in some models). These trucks are highly sought after by collectors and enthusiasts for their ruggedness, character, and nostalgia. Owning one allows you to be part of a community that appreciates vintage American muscle and work trucks.

2. **Potential for Restoration or Customization**

Many 1980s F-Series trucks are undervalued compared to their modern or restored counterparts. A project truck like this can be a rewarding long-term investment if you enjoy working on cars. The auxiliary 25-gallon fuel tank adds a unique touch, making it stand out from standard models. With proper restoration, this truck could become a showpiece or a highly modified daily driver.

3. **Reliability of the 5.0L V8 (if equipped)**

The 5.0L (302 cubic inch) V8, introduced in 1986, is one of the most beloved Ford engines. It s known for its durability, strong aftermarket support, and ability to handle modifications (e.g., forced induction, big blocks). If the truck has this engine, it s a major selling point. The 4-speed automatic (C4) or 5-speed manual (C6) transmissions are also reliable, though the C4 can be finicky without proper maintenance.

4. **Auxiliary Fuel Tank as a Unique Feature**

The 25-gallon auxiliary tank is a rare modification that can extend range significantly, which is useful for off-roading, long trips, or as a novelty feature. If the tank is properly installed and maintained, it could be a practical upgrade rather than a liability.

5. **Lower Purchase Price**

Classic F-Series trucks from the 1980s are often sold at reasonable prices compared to newer or fully restored models. This makes it an affordable entry point into truck ownership, especially for those who prioritize the driving experience over modern conveniences.

6. **Off-Road and Utility Potential**

The body style (Blazer/Suburban) and chassis of these trucks were designed for rugged use. With some modifications, they can handle light off-roading, towing, or utility work. The auxiliary tank could be particularly useful for remote jobsites or camping trips.

7. **Community and Enthusiast Appeal**

Owning a classic Ford from this era opens doors to a passionate community of owners, restorers, and modifiers. Events like truck shows, swap meets, and club rallies provide opportunities to connect with like-minded individuals and share knowledge.

---

### **Cons of Buying This Vehicle**

1. **Fuel Sending Unit Issues**

- **False fuel readings** (e.g., gauge showing "E" when there s still fuel, or vice versa).

- **Difficulty starting the truck** if the gauge fails completely, as you won t know when the tank is empty.

- **Potential fuel starvation** if the sending unit is faulty and the float mechanism gets stuck, cutting off fuel flow prematurely.

The repair cost for a new sending unit (or a rebuilt one) can range from $100 to $300, depending on availability and labor. If the gauge itself is also failing, replacement may be necessary.

2. **Age-Related Wear and Tear**

- **Worn suspension components** (shocks, bushings, ball joints) that affect ride quality and handling.

- **Rust** in critical areas like the frame, wheel wells, and undercarriage, which can compromise structural integrity.

- **Exhaust and emissions systems** that may need replacement or tuning to meet modern standards (though many classic trucks are exempt from smog checks in some states).

- **Electrical issues** common in older vehicles, such as failing alternators, starters, or wiring harnesses.

3. **Maintenance and Parts Availability**

While parts for 1980s F-Series trucks are widely available, some components (especially aftermarket or rare items) can be expensive or difficult to source. The auxiliary fuel tank may require custom fittings or modifications to integrate properly with the stock system. You ll need to ensure the tank is compatible with the truck s fuel lines and pump.

4. **Fuel System Modifications Can Be Complex**

- **Fuel line leaks** or improper routing, which can lead to spills or fire hazards.

- **Incompatibility with the stock fuel pump or injectors** (if the truck is fuel-injected), which could strain the system or reduce performance.

- **Air intake issues** if the auxiliary tank disrupts the fuel/air ratio, leading to rough idling or poor acceleration.

Consulting with a mechanic or fuel system specialist is advisable before proceeding with any modifications.

5. **Reliability of the Transmission**

- **Slipping or delayed shifts** due to worn bands or solenoids.

- **Torque converter issues** that can cause overheating or failure.

- **Fluid leaks** from the transmission or cooler.

The 5-speed manual (C6) is more reliable but may require synchronization adjustments over time.

6. **Modern Driving and Safety Concerns**

- **Lack of modern safety features** (e.g., ABS, stability control, airbags beyond the driver s side).

- **Poor fuel economy** compared to modern trucks, which can be costly for daily use.

- **Inferior visibility** due to larger body styles and less advanced driver aids.

- **Higher insurance costs** for classic or modified trucks, especially if used for daily driving.

7. **Time and Effort Required**

- **Regular maintenance** (oil changes, brake service, fluid flushes).

- **Paint and bodywork** if the truck is rusted or damaged.

- **Interior updates** (seats, dashboard, wiring) to make it comfortable for daily use.

- **Testing and tuning** after modifications, especially with the auxiliary fuel tank.

8. **Resale Value and Depreciation**

While classic trucks can appreciate in value, they also depreciate quickly if not maintained or restored. The auxiliary tank and fuel sending unit issues could further reduce resale appeal unless the truck is heavily modified or restored to showroom condition.

---

### **Conclusion**

Buying a 1987 Ford F-Series (F-12, Blazer, or Suburban) with a fuel sending unit issue and an auxiliary 25-gallon fuel tank is a decision that hinges on your priorities. If you re an enthusiast who enjoys working on projects, appreciates vintage trucks, and is willing to invest time and money into restoration, this could be a rewarding purchase. The auxiliary tank adds a unique character, and the 5.0L V8 (if present) is a fantastic engine to work with.

However, if you re looking for a reliable, low-maintenance daily driver or a truck that meets modern safety and efficiency standards, this purchase may not be the best fit. The fuel sending unit issue is a critical fix that shouldn t be overlooked, and the auxiliary tank requires careful integration to avoid complications. Additionally, the age of the truck means you ll need to be prepared for ongoing maintenance and potential repairs.

---

### **Recommendation**

- **Proceed with caution.** Prioritize fixing the fuel sending unit and inspecting the auxiliary tank system for leaks or compatibility issues.

- **Budget for a full inspection** by a trusted mechanic to assess the condition of the engine, transmission, suspension, and electrical system.

- **Consider a restoration plan** if you re committed to bringing the truck back to showroom condition. Join classic Ford forums or clubs for advice on sourcing parts and techniques.

- **Test the truck thoroughly** before finalizing the purchase, including a long drive to check for leaks, fuel delivery, and overall reliability.

- **Look for a more modern or restored example** of the same body style, or consider a newer classic (e.g., 1990s F-Series) that offers better reliability and modern conveniences.

- **Avoid trucks with major mechanical issues** unless you re prepared for the long-term commitment of repairs.

- **Consider a used but well-maintained truck** with a clean title and service records to minimize surprises.

- **Research fuel system modifications** to ensure the tank can be safely and effectively integrated

Details:

1987 Blazer/Jimmy/Suburban Fuel Sending Unit-25 Gallon Tank-4 Out.

part #: fg12k prices

• $76.40-$99.42

specifications fueltanksysteme:

• for models: Blazer, Jimmy, Suburban
• for years: 1987
• brand: Classic Industries
• mpn: Fg12k
• part type: Fuel Sending
• item height: 16

returns fueltanksysteme:

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

payments fueltanksysteme:

• other
• credit card: Discover
• wallet: Paypal

shipping fueltanksysteme:

• service: USPS Ground Advantage, UPS Ground, UPS 2nd Day Air, FedEx Ground / FedEx Home Delivery
• carrier: USPS, UPS, FedEx
• type: Calculated
• cost: $12.34
• transit: 4-10 Days
• class: Standard, Expedited

seller fueltanksysteme:

• # reviews: 59958
• rating: 99.7%
• city: Huntington Beach, California

general fueltanksysteme:

• Car Truck Parts Accessories > Air Fuel Delivery > Fuel Tanks Filler Necks
• condition: New

offer fueltanksysteme:

• started: May 4, 2026
• quantity: 10
• availability: In Stock
• sold: 0
• options: Ship-to-home

Classic Industries FG12K Is Similar To:

• Agt-bfik90 Classic Performance Fuel Tank Installation Kit (34% similar) Buyer pays return shipping. Fuel pump included no notes 90 ohm sending unit, designed to be used with CPO aluminum bed fill flush gas tanks only. Image to purchase these items below and complete your installation...(June 17th, 2018)
• Agt-btank 5760 Classic Performance Products Cpp Ton Truck Aluminum Fuel Gas Tank (30.6% similar) Steering brakes suspension call the experts ford 1/2 ton truck aluminum fuel 15 gallon gas tank these tanks are a must for anyone wanting move original from behind seat to under bed, between frame rails. A roll over valve is also included - that will stop gas from spilling out if the tank would ...(November 9th, 2018)
• Gm20d Various Models Chart Bob S Classic Chevy Buick Olds Pontaic 1996-99 Gm Pontiac Premium Zinc Galvanized Gas Fuel Tank (27.4% similar) This top quality, exact reproduction gm gas fuel tank from bob's Classic Chevy is made to the same specifications as the original, and has an oem zinc galvanized finish inside and out for maximum corrosion protection. Fits the following model's Buick Sabre Oldsmobile Oldsmobile Oldsmobile Las ...(August 25th, 2016)
• 4753agt-bf Classic Performance Products Cpp Chevy Truck Gas Tank Aluminum Bed Fill 1947-1953 (29.7% similar) Once the tanks are installed, fuel can be serviced through the bed floor, or custom side fills can be added. Sending unit is not included aluminium and tog welded. These tanks are pre notched for leaf spring clearance and install without having to move the cross members. Replacement TANK22 gallon ...(October 23rd, 2016)
• Mur1024-oe Classic Tube Mustang Fuel Return Line Steel 1996-98 (34.2% similar) Easily mounting into place, this fuel line connects your fuel tank and fuel rails, so any unused fuel can return to the tank smoothly. Direct fit replacement original steel construction allows unused fuel to smoothly return to fuel tank pre bent to easily utilize factory connections made in the USA ...(May 16th, 2016)
• Gt13-553s Golden Star Classic Auto Parts Chevy Sending Unit Line Except (39.8% similar) Fits: Chevy hardtop, convertible, sedan 150, 210 Bela air 2 door 4 except station wagon, delivery nomad...(November 23rd, 2018)
• Qp03-681fd Golden Star Classic Auto Parts Elcamino Fuel Tank Door (36.1% similar) Fits: Alcmena. New exact reproduction of the original...(November 25th, 2018)
• Sn33 Classic Instruments Adjustable Fuel Tank Sending Unit 013110000648 (48.4% similar) Classic instruments SN33 adjustable fuel tank sending unit UNIT240-33 ohms features ohm heavy-duty sensor movement. Note: not for use in foam filled cell applications. The stainless steel mounting plate uses a 3/8 outside diameter x 13 pick-up tube that can be shortened to match tank depth. The ...(March 21st, 2019)
• Sn35 Classic Instruments Adjustable Fuel Tank Sending Unit 013110000464 (48.4% similar) ...(March 20th, 2019)
• Sn39 Classic Instruments Ohm Range Fuel Level Sending Unit (50% similar) Addresses at this time. Virgin islands. Electrical or electronic components are also void if they have been connected opened. In-stock items can ship from multiple locations...(July 19th, 2018)
• Ts28b Auto City Classic Ford Merc Gas Tank With Sender Straps (29.1% similar) Replacement gas tank for 1956 ford and mercury passenger cars direct TANK17...(November 16th, 2018)