As a long-time Jeep CJ enthusiast and owner, I understand the unique charm of these classic vehicles. For over 30 years, I’ve experienced the joys and quirks of CJ Jeeps, currently owning a 1986 CJ7 that I cherish for summer drives and off-road adventures. However, let’s face it, while vintage Jeeps like the CJ7 are iconic, automotive technology has advanced significantly since their production. For those of us who use our CJ7s regularly and appreciate modern driving standards, certain upgrades can dramatically improve the experience without sacrificing the Jeep’s inherent character.
This guide, based on my personal hands-on experience, outlines essential upgrades that prioritize enhanced performance, reliability, and a more enjoyable driving experience for your Jeep Cj7. If you’re a purist focused solely on originality, these modifications might not be for you. Please note that while I mention prices, these are based on past purchases and current costs may vary. This list is subjective and reflects upgrades I’ve personally found most beneficial for casual driving and Jeep events.
1. Brighter Headlights: Enhanced Visibility and Safety
One of the most noticeable shortcomings of a classic Jeep CJ7 is its factory headlights. Compared to modern vehicle lighting, the original CJ headlights are dim, offering poor visibility, especially at night. This isn’t just an inconvenience; it’s a genuine safety concern. Driving a CJ7 at night with stock headlights can feel like navigating with candles! The original wiring system in CJ7s is also inadequate for powering modern, brighter bulbs.
Thankfully, a straightforward and effective solution exists: upgrading to H4 conversion headlights with a relay wiring harness. Wiring kits are available that utilize 12V relays to draw power directly from the battery, bypassing the original, undersized wiring. This ensures sufficient power for brighter bulbs and protects your original headlight switch. These kits are designed for easy, plug-and-play installation, often connecting directly to your existing wiring harness, maintaining the function of your dashboard light controls without any soldering.
For the lens itself, consider H4 Rampage Conversion lenses or similar, readily available from Jeep parts retailers. These lenses accept modern H4 halogen bulbs, offering a significant improvement in brightness. Warning: Avoid using H4 halogen bulbs with the original CJ7 wiring as it can overheat and damage your headlight switch.
Installation of the wiring kit and lenses is typically straightforward, involving routing wires and securing connections with zip ties. Aiming the new headlights is crucial and will require adjustment. A helpful tip is to note the current aim of your stock headlights before replacement (using masking tape on a wall at night on level ground) as a starting point. The goal is to maximize road illumination without blinding oncoming drivers. This may require several adjustments and test drives at night. Remember, headlights should be aimed downwards to illuminate the road ahead, not upwards or level. Numerous online resources and YouTube videos provide detailed guidance on headlight aiming procedures.
2. HEI Ignition: Reliable Performance and Easier Starts
The original Motorcraft ignition systems found in CJ7s, whether equipped with the inline-six or V8 engines, represent older technology prone to weak spark and failures. Many CJ owners, myself included, have experienced control module failures, often carrying a spare module as a precaution. A significant upgrade in reliability and performance is the General Motors High Energy Ignition (HEI) system. HEI is renowned for its robust spark, dependability, and affordability, making it an ideal conversion for Jeep CJ engines.
GM HEI conversion kits designed for AMC engines are readily available for under $120 online marketplaces or from Jeep parts specialists. These kits are compatible with both the 258 inline-six and AMC 304 V8 engines.
Having personally used an eBay-sourced HEI distributor for over 8 years without issue, I can attest to its durability and effectiveness. HEI systems feature a simple one-wire connection and are widely copied, ensuring parts availability. Coupled with modern 8mm spark plug wires, an HEI upgrade results in smoother engine idling and noticeably easier starting, improvements I’ve directly experienced. You can even retain your original spark plugs.
Installation involves basic wiring, as the HEI system typically requires just two wires (12V ignition and tachometer signal) and a vacuum line connection to the carburetor for timing advance. Wiring diagrams and a multimeter are helpful for identifying the necessary connections on your CJ7. The improvement in engine performance and starting reliability makes this a highly recommended and cost-effective upgrade.
3. Steering Slop Upgrade: Tighter and More Responsive Control
“CJ steering slop” is a common complaint among CJ7 owners. The vague and wandering steering feel can be frustrating and detract from the driving experience. Fortunately, significant improvement is achievable, bringing your CJ7 steering closer to modern standards. This upgrade involves three key components: a 2-inch muffler clamp, a Crown Automotive heavy-duty steering shaft, and a power steering gearbox sourced from a Jeep J20 pickup truck.
The J20 steering gearbox is the core of this upgrade. It offers a tighter feel and variable rate turning, similar to modern power steering systems, making highway driving and maneuvering much more controlled. It’s a direct bolt-on replacement for the CJ7 gearbox. Rebuilt J20 gearboxes are readily available from auto parts stores.
The heavy-duty steering shaft replaces the original CJ shaft, often contributing to steering play. The muffler clamp addresses play in the plastic bushing where the steering shaft passes through the firewall. Install the clamp around this bushing and gently tighten it to reduce slop, being careful not to overtighten and damage the plastic.
Important Note: The J20 steering box spline is designed for manual steering shafts. Ensure you purchase a heavy-duty manual steering shaft for compatibility. The J20 box will not directly fit the original CJ7 power steering shaft. This comprehensive steering upgrade significantly reduces play and provides a more confident and modern steering feel.
4. Better Suspension: Enhanced Ride Comfort
The stiff leaf spring suspension of classic Jeeps, including the CJ7, is a hallmark of their ruggedness but can result in a harsh ride, especially by modern standards. As a CJ7 owner who values comfort, particularly on longer drives, upgrading the suspension was a game-changer. Modern leaf spring technology has advanced considerably, offering improved ride quality even within leaf spring designs.
For CJ7 suspension upgrades, I highly recommend Old Man Emu (OME) leaf springs designed for the Jeep Wrangler YJ series. These springs are compatible with CJ7s with a minor modification to the front shackle brackets. A readily available YJ to CJ conversion bracket resolves this, allowing for a seamless installation of YJ springs on a CJ7.
For a complete suspension overhaul, replace all components, including rubber bushings, bolts, leaf springs, shackles, shocks, U-bolts, spring plates, and consider longer rubber brake lines to accommodate increased suspension travel. Based on recommendations, I opted for Old Man Emu CS036R medium-duty springs (set of 4) which provide approximately 2.5 inches of lift. While the increased ride height slightly raises the vehicle, accessibility remains manageable.
Although a more significant investment (around $800 for a complete kit), the Old Man Emu suspension upgrade dramatically improves ride comfort. The difference is so noticeable that other CJ owners who have experienced my Jeep’s ride have subsequently opted for the same upgrade. Installation is achievable over a weekend and well worth the investment for anyone seeking a more comfortable ride from their CJ7.
Note: If YJ to CJ conversion shackles are unavailable, consider using new YJ front shackle hangers with standard YJ 2.5-inch front shackles as an alternative.
5. Better Seats: Improved Comfort and Support
A broken passenger seat in my CJ7 initiated my search for aftermarket seat replacements. While the original CJ7 seats are adequate, they lack the side support found in modern seats. Having become accustomed to this support, I sought similar seats for my CJ7. Seat preference is subjective, so testing seats in person is recommended. Jeep shows and swap meets often have seats on display for testing.
After trying various options, I chose Corbeau Sport Seats from a Jeep parts supplier. While priced around $300 each, the improvement in comfort and support is significant. These seats offer enhanced side bolstering, holding you more securely than the original seats.
Although designed for a YJ Wrangler, installation in a CJ7 was straightforward, requiring only drilling an extra set of holes in the existing CJ7 seat brackets. Combined with the upgraded suspension, these seats make the CJ7 a significantly more comfortable vehicle for both short trips and longer drives. To complete the look, I added a matching rear seat cover, retaining the original folding rear seat.
6. Better Engine Cooling: Preventing Overheating
The standard 4-blade engine fan commonly found on CJ7s with inline-six engines is barely adequate, particularly for V8-equipped models. Having experienced overheating issues after upgrading to a V8, improving engine cooling became essential. While the stock 3-core radiator is generally sufficient, the fan is a weak point. Electric fan conversions are a viable option, but I found a simpler and effective solution: a 7-blade clutch fan from a Jeep Wagoneer. This fan bolts directly onto the CJ7. To further enhance cooling efficiency, I added an aftermarket fan shroud.
The difference in airflow with the 7-blade fan and shroud is remarkable. The increased airflow through the radiator significantly improves cooling efficiency, particularly noticeable in hot weather or during demanding driving conditions. The improvement was so dramatic that it was immediately apparent in the increased suction at the front grille.
Honorable Mentions:
Beyond these key upgrades, several other modifications can further enhance your CJ7. These are often more involved to install and may not be necessary for all CJ7 owners, but are worth considering depending on your needs and intended use:
- Upgraded heater blower fan: A GM Blazer blower motor upgrade provides significantly improved heater performance.
- Plastic gas tank: Replacing a leaky metal fuel tank with a plastic tank eliminates rust and potential leaks.
- One-piece axles for AMC 20 rear end: While not essential for inline-six CJ7s, one-piece axles strengthen the AMC 20 rear axle, particularly beneficial for V8 models or those used for more demanding off-roading.
These upgrades represent my personal recommendations for enhancing the driving experience of a Jeep CJ7, based on years of ownership and hands-on modifications. While maintaining the classic Jeep charm, these improvements address key areas where modern technology offers tangible benefits in performance, reliability, and comfort.
