Hidden Gem: Third-Gen, Cummins Diesel-Powered Dodge Ram

• December 26, 2023
• Story By
  Mike McGlothlin

They’re out there. Ultra-clean, older trucks that’ve all but become collector items. In the aftermath of the diesel emissions crunch, the Cummins-powered ’03-’07 Dodge Rams are a hot commodity, but finding rust-free, low-mile versions is becoming more and more rare. These 2500 and 3500 model trucks represent the last ride for the 5.9L inline-six, before it became a 6.7L saddled with EGR, a DPF and, eventually, SCR. Long story short, Paul Szczypta found a third-gen that would be the envy of any diesel enthusiast: an immaculate ’07 with zero rust and just 113,000 miles on the clock.

But Paul’s third-gen is much more than simply a mint condition survivor. It’s packing a built engine with plenty of fuel, a big single turbo and a competition-ready transmission that allows it to route more than 800 hp to the wheels. And thanks to a set of 24x12-inch American Forces, it does it in style. Join us for the full tour of Paul’s flawless, straight bodied Dodge, a hard-to-find truck that serves as his daily-driver and weekend play toy in fairer weather—as well as a truck that epitomizes the modern era of diesel performance.

A Well-Preserved Survivor

Believe it or not, Paul Szczypta’s ’07 Dodge Ram 2500 has been a Midwest truck most of its life, and after he found it out in West Virginia it promptly returned to a northern climate—where salty roads and rusting body panels are par for the course. Unbelievably, despite the truck’s exposure to the elements over the past 16 years (it was never stored inside), it sits in incredible, practically perfect shape. The paint is original, the odometer shows just 113,000 miles and the interior is like brand-new. Cosmetic and stance upgrades include clear headlights, Recon smoked cab lights, taillights and third brake light, Boost Auto fourth-gen mirrors, a 2.5-inch drop up front and three fewer leaf springs in the rear.

Mildly-Built 5.9L Cummins

Beneath the posh KingSpeed valve cover (and beside the sizable single turbo we’ll talk about next) lies a 5.9L common-rail Cummins that’s been treated to a host of upgrades. ARP main studs, Wagler Competition Products' Streetfighter rods and valve-relieved Mahle pistons reside in the factory bore block. Up top, you’ll find a Stage 1 head from D&J Precision Machine (both the block and head were cut to accept fire-rings), complete with 5-axis port work, 105-lb valve springs and 220 cfm worth of flow on the intake side (vs. 155 cfm stock). The high-flow head is fastened to the block via ARP Custom Age 625+ head studs.

5-Blade Turbo

Boost comes in the form of an S400-based turbo from Stainless Diesel. The big single sports a billet, 5-blade compressor wheel with a 75mm inducer, an 87mm turbine wheel, a spool-friendly 1.0 A/R exhaust housing and forces 55 psi of boost through a Banks intercooler. The compressor housing is polished and the exhaust housing has been hot ceramic dipped so it won’t discolor or rust. It hangs from a T4 Steed Speed exhaust manifold and routes exhaust out a 4-inch downpipe that’s connected to a custom, 5-inch conventional exit exhaust system.

4-Digit Horsepower Potential

The Cummins’ common-rail injection system benefits from the S&S Diesel Motorsport 14mm stroker CP3 you see pictured here. The high-pressure fuel pump—which can support north of 1,400 hp— sits in the factory location and feeds 26,000-plus psi to a larger, 6.7L Cummins-sourced fuel rail. Completing the recipe is a set of 200-percent over injectors, also from S&S. Spot-on ECM tweaks from Hardway Performance’s Ryan Milliken ensure the truck remains drivable, clean-burning, powerful and reliable.

Steady Fuel Supply

In direct support of the engine’s injection system mods, an AirDog II-5G fuel supply system resides along the driver side frame rail. It’s neither seen or heard, but it’s 100-percent vital to the Ram’s 800rwhp combination. The 4G lift pump quietly pulls fuel from the factory tank, sending it to the 14mm CP3 by way of ½-inch fuel hose. Running at full operating potential, the AirDog system can flow 165 gallons per hour (gph). Also notice the 5-inch exhaust system and one of the truck’s two traction bars in the background.

Manually-Shifted 48RE Transmission

Thanks to its coat of gold paint, the 48RE transmission is instantly recognizable as a Firepunk Diesel unit. This particular four-speed automatic is one of the company’s Comp 3 builds, complete with a solid, 37-spline input shaft, Sonnax billet intermediate and TCS fat billet output shaft. Aiding spool up of the big single and providing sound overall drivability is a four-disc DPC torque converter boasting a 2,400-rpm stall speed. For complete control over the 48RE’s shift points and converter lockup, the transmission is fitted with a full manual, high-pressure valvebody from Power Driven Diesel.

Unblemished Interior

For a nearly 17-year-old third-gen, it doesn’t get much better than this. Untorn and unworn leather seats say the 113,000-mile Ram has barely been lived in. However, although the original, SLT trim seats, center console and door panels were in impeccable condition for our photo shoot, Paul tells us he has since ditched them in favor of SRT10 replacements. In-cab entertainment (other than the truck’s tire-melting 1,500 lb-ft of torque) comes in the form of a Sony stereo receiver with an 11-inch screen and two 12-inch subs located under the rear seats.

420V’s And 24’s

Finding traction is a formidable task for any tire in a high torque diesel application, but Paul says the Nitto NT420V all seasons do the best they can—and that when locked in 4-High tire slip is a non-issue. Each 305/35R24 luxury truck and SUV tire measures 32.5-inches in overall diameter and roughly 12.4-inches wide. They’re mounted on polished, 24x12-inch Independence model wheels from American Force—a wheel and tire combination that brings the old third-gen into the modern age.