We recently picked up a 1998 Dodge 2500 Quad Cab with the coveted 12-valve Cummins engine. This illustrious truck is hard to find because in 1998 they began producing the four-door cab, but it was only produced for about six months with the 12-valve engine before Chrysler began fitting the trucks with the electronically controlled 24-valve ISB Cummins. The 12-valve engine is "built like they used to be"-simple, dependable, and unadulterated by some of today's potentially troublesome electronics and miles of wiring. The internals are stronger and more overbuilt in many ways than the current common rail Cummins. Oh, and did we mention they often get much better fuel economy than the 6.7- and even 5.9-liter common rail engines?
The idea is to build a truck that will serve a few purposes: be reliable, get good fuel economy, be an absolute blast to drive, kick the snot out of 98 percent of any diesel truck or punk in a car that may pull up next to you at a stop light, be respectable on the drag strip on the weekend, and be a daily driver. Seems like a pretty reasonable list of expectations, right?! We should also define "daily driver" too. Typically, you can build a 12-valve engine up to about 450-500hp and it will be pretty streetable. Build it for much more than that and they become pretty smoky when driving around town. These engines are rock solid, but they lack the sophisticated tuning that the computerized engines and transmissions have, so you either tune them for daily driving or race applications. Our goal is to cross over into both worlds by getting serious about mechanical tuning. This tuning will need to take place throughout every component of the engine and transmission. Fuel, air, timing, compression, torque converter and transmission will all have to be dialed. Let's face it, these days it's not cool to be constantly belching black smoke into the air as you drive. It looks bad, it's not considerate to the cars behind you, and it's annoying to see all of that wasted fuel come out of the tailpipe as you drive. Our goal with this truck is efficient power. Finally, we finish up our list of to-do's for this project by trying to provide a unique but viable alternative to many of us who don't want to drop $50K on a new truck. We'll spend some money on this build, but we'd like the end result to be everything we've listed above, which we think could be a great alternative to dropping all that cash on a new truck. The other great thing about building an old truck is that you can put money into it at your own pace.