68RFE 6.7L Dodge Cummins Mega Cab

Derrick Barney’s 1,400HP, 68RFE Shifted ’11 Mega Cab

When a rod left the block of his 6.7L Cummins a few short years ago, Derrick Barney never could’ve imagined that he would soon own one of the most powerful—and reliable 68RFE equipped Rams in the country. But that’s exactly what you’re about to read about in the following pages. He had a new engine built, and has added dual CP3’s, upsized injectors, and went from an S472 to a single S480 in his un-ending search for more power. Along the way, he’s dealt with the trials, tribulations, and (of course) monetary setbacks that come with st icking it out with Chrysler’s notorious six-speed automatic. However, if you cross paths with him, he’ll tell you it was worth every second.

Fresh Start, Stronger Foundation

Starting with a fresh block, Derrick pulled out all the stops in making sure a hard-part failure never struck again. The mains are now tethered together courtesy of a Gorilla Girdle and ARP main studs from Industrial Injection while the rest of the short-block consists of Carrillo rods mated to ceramic coated factory replacement pistons. The head was transformed into one of Freedom Racing Engine’s Street HD units, with hardened and oversize valve seats, 105-lb valve springs, and threaded freeze plugs. ARP Custom Age 625+ head studs fasten it to the block.

2nd-Gen Turbo Swap, S480 and Competition Manifold

When Derrick initially took the factory Holset VGT out of the equation in favor of Stainless Diesel’s second-gen turbo swap kit, he didn’t jump straight into running the S480. Rather, after running one of Stainless’ T4 S472 chargers (a 72/87/1.0 that allowed 894-rwhp to be made on the rollers), he wanted to take things even further. The switch to the current 5-blade S480, an 80/96/1.15 with a T6 foot, brought more than 200 more ponies into the picture. Now his biggest problem is the fact that the truck runs out of road long before it runs out of air. Complementing the S480 is a Stainless T-6 24-valve Competition exhaust manifold, which—with its full-length 1.65-inch diameter internal runners—makes spool up a non-issue and the truck extremely drivable on the street.

Dual CP3’s and 350hp Injectors

Adequate rail pressure is always on tap thanks to H&S Motorsports’ dual high-pressure fuel kit. Both the factory location CP3 and the second, belt-driven pump are stock 6.7L Bosch units. A ported rail supports the effort and injectors fitted with 152-percent over Industrial Injection nozzles handle in-cylinder fuel delivery. Given the nozzles’ size, which Industrial also refers to as its 350hp units, just under 1,100-rwhp can be made on fuel with a CTT Tuning that calls for just 2,250 microseconds worth of duration. Feeding the CP3’s all the low-pressure fuel they need is left to a 165-gph AirDog II system.

Sticking With The ‘68

Every ’07.5-present Dodge Cummins owner that’s pursued horsepower in conjunction with the 68RFE platform has a story to tell, and Derrick is no different. Back before the truck lost all of its innocence, Derrick campaigned a Signature Series 700 from RevMax, which tolerated three years’ worth of abuse before requiring some TLC. He then upgraded to RevMax’s Signature Series 850 for a bit, but had to regroup once again when the stakes went even higher. At the present time, there is a host of one-off and even prototype parts stacked inside the transmission case. Pieced together at White Knuckles Garage, the 68RFE features a custom-machined 300M 4th hub and RevMax XR input drum from Randy’s Transmissions, a billet-steel center support, a maraging steel input shaft, and Randy’s Baby Maker 1000 valve body. The torque converter is a billet, triple-disc unit from RevMax, with a 2,200-rpm stall speed.

Trail-Blazing

Countless 6.7L Cummins owners bid the 68RFE farewell long before they pursue the kind of power Derrick’s Mega Cab is making, the most common reason being the questionable reliability of a built ’68 given the amount of money spent. Luckily for us, Derrick does things differently than most… and the battle-tested six-speed in his Mega Cab has had 1,436 hp and 2,578 lb-ft of torque squeezed through it and lived to tell the tale. On top of that, it’s also been subjected to more than 20 boosted four-wheel-drive launches (in first gear, no less) and gone up against some pretty nasty streetcars on the local no-prep scene. Derrick credits longtime horsepower junkie and close personal friend, Stephen O’Neal of White Knuckles Garage, for building him a transmission capable of surviving so much abuse. Every time he hits the street, dyno, or track, Derrick and his 8,100-pound Mega Cab prove that you can have your cake and eat it, too in the world of the infamous 68RFE.