The 2025 Ram Arrives—With A Completely Revamped Cummins

Last week, the 2025 Ram 2500 and 3500 Heavy Duty’s were unveiled, and the biggest news (at least for us) revolved around the powertrain. New for ’25, the 6.7L Cummins gets top-feed style injectors and top-side accessible oil and fuel filters, a Bosch CP8 high-pressure fuel pump that’s said to be a new-and-improved rendition of the CP4.2, a quicker-responding VGT, a bolt-on, side-draft style intake manifold and, for the first time ever, glow plugs instead of a grid heater. By all accounts, the hydraulic lifters introduced in 2019 remain. The new, now cast-iron block (no more CGI) 6.7L Cummins produces 430 hp and 1,075 lb-ft of torque across the board, with a high output engine option no longer being offered. The revamped I-6 will be tethered to a diesel-specific version of the ZF-built 8HP75 eight-speed automatic transmission, which many have high hopes for.

In The Dirt

Headed For The Sand

It hasn’t taken very long for Nick Zaenkert’s new “High Stakes” build to put the rest of the 3.0 Limited Pro Stock class on notice. Over the weekend, Nick’s brand-new, E&M Repair And Fabrication-built Super Duty—complete with a fire-breathing common-rail Cummins from Freedom Racing Engines under the hood, took the win at the 2025 Midwest Winter Nationals in Cloverdale, Indiana. On his way to the winner’s circle, Nick had to beat out the likes of Ryan Perkins (“Perkins Brothers” second-gen) and Jason Wayman (“Megatron”). As usual, the pros at Built Diesel Mafia were front-and-center at the show, capturing all the action on video, and you can watch Nick’s Super Duty make its 296-foot run at the sand pile here.

How To Become A Horsepower Junky 101

The Diesel Bug—In A Nutshell

In less than 100 words, Nathan Wheeler, owner of the street-racing, D&J Cummins-powered 2010 Ford F-250 known as “Crazyhorse,” summed up the highly relatable path he took in his diesel addiction—and he absolutely nailed it. “It starts with a work vehicle… Morphs into a bolt-on stock powerhouse. Super cool. Someone beats you… The engine comes out for hard parts and a bigger turbo. Transmission breaks… This is the worst! You have to buy an expensive trans! [But] now you have a “sleeper.” Super cool. Someone beats you. Empty that wallet…don’t even think about the cost. Borrow from Grandma (she’s rich, don’t feel bad) JK. Build the ultimate labor of love that doesn’t make a lick of sense!” The photo above represents Nathan’s Super Duty at the peak of its daily-driven, sleeper stage.

Modified Classifieds

5.0L Cummins-Powered C10 To Be Auctioned Off

TV personality Kevin Tetz’s project “C-Tane” goes on the Mecum Auctions’ block this Saturday. Known as the world’s first 5.0L Cummins V-8 powered Chevrolet C10, it sports an engine out of a donor Nissan Titan XD, as well as an Aisin A466ND transmission. But there’s much, much more. Thanks to the craftsmanship of the late Joshua Chapman (of CFT Performance), the engine boasts a single, Stainless Diesel 5-blade S300 rather than the factory compound arrangement. The reskinned C10 also sits on a Schwartz Performance chassis, enjoys a 49/51 weight bias, and makes roughly 600 hp and 1,000 lb-ft of torque. It will be very interesting to see how much it goes for.

Carnage Corner

Cataclysmic CP4.2 Failure

Unfortunately for far too many 6.7L Power Stroke owners, this is how some CP4.2 high-pressure fuel pumps meet their fate. Instead of simply failing internally (which is bad enough), the pump’s case literally explodes, becoming a multi-piece unit. The Super Duty that suffered this CP4.2 failure was brought to the folks at Hollyrock Customs and, luckily, the 170,000-mile engine had previously been fitted with one of S&S Diesel Motorsport’s disaster prevention kits. This means that, while the CP4 is obviously trashed, the injectors, rails, tank, and lift pump are not. According to Hollyrock, the owner will be upgrading to one of S&S’s DCR pump conversions for ultimate peace of mind and reliability.

Written by Mike McGlothlin