Cummins Conversions -
5.9L Cummins Diesel Conversions
Variety is the spice of life!

The 5.9L Cummins has to be the single most popular choice for a diesel conversion. Plentiful, relatively inexpensive, simple electrical requirements, enormous aftermarket support, proven reliability and a satisfying power potential all make the Cummins a popular choice. This month we present four 5.9L Cummins conversions in four very different types of vehicles that demonstrate this popularity and versatility.

Cummins Conversions -
  • Owner: Chris Preputin
  • Truck: 1986 Chevy K2500 Suburban
  • Engine: 1993 Dodge 5.9L 12-valve Cummins
  • Fuel Injection System: Bosch P7100 mechanical fuel injection pump
  • Chassis: Stock frame w/6" suspension lift
  • Performance: 244 rear wheel horsepower

Originally equipped with a 6.2L diesel, this Suburban was purchased new by Chris' father in 1986 who dropped in the Cummins seven years later in 1993. This is one of the earliest Cummins conversions I've heard about. Through all these years since completing the conversion, the Cummins has proven itself reliable and economical for Chris and his family. Chris says reliability was key motivation for this conversion from the very beginning, which meant big power was not a primary goal. Always a great looking Suburban with its custom paint recent upgrades included new tires and wheels and more polish.

Cummins Conversions -

The Cummins is accessorized with aluminum valve covers and a Banks intake. Engine cooling is aided by a set of Flex-a-Lite electric fans.

Cummins Conversions -

The large Spearco/Turbonetics intercooler just squeezes into the available space behind the grille.

Cummins Conversions -

Cummins Conversions -
  • Owner: Geoffrey Wise
  • Truck: 1956 Ford F-100
  • Engine/Trans: 1999 Dodge 5.9L 24-valve Cummins / 47RE 4-speed automatic
  • Fuel Injection System: Bosch VP-44 w/Edge EZ (+50 hp setting), FASS Fuel Filtration/lift pump
  • Chassis: Boxed stock frame rails w/Mustang II independent front suspension, Ford 8" rear differential w/2.80:1 gearing
  • Weight: 4200-lbs
  • Performance: 25-mpg local driving
Cummins Conversions -

The '56 looked right at home at a classic car meet where these photos were taken, yet it is quickly set apart when the hood is tilted forward. The heart of this truck is set to the beat of a 5.9L Cummins turbo diesel.

Cummins Conversions -

Unlike most who embark on a Cummins conversion project, owner Geoffrey Wise chose to retain the electronically-controlled Bosch VP-44 fuel injection system and 47RE 4-speed automatic transmission. I first saw this truck nearly 4 years ago when it was still in primer, while the techs at US Diesel Parts ( were lending a hand in getting the electronics sorted out. The non-intercooled 5.9L fits well into the engine bay, and there's even room for an engine-driven fan. The tilt hood eases any sort of maintenance access. An electronic engine allows full use of currently available electronic performance products, such as the Edge EZ, which looks right at home.

Cummins Conversions -
Cummins Conversions -

Suicide doors adds something special, and Geoffrey installed the 1999 Dodge steering column and instrument panel, which added functionality and made completing the electronic portion of the installation a lot easier.

Cummins Conversions -

The dyno results weren't recorded (150-200ish range), but they did strap the '56 to the dyno at a recent dyno event - for crowd control, everyone really wanted to see it run.

Cummins Conversions -
  • Owner: Denny Haugen
  • Truck: 1969 Toyota FJ40
  • Engine: 1997 Dodge 5.9L 12-valve Cummins
  • Fuel Injection System: P7100 mechanical fuel injection pump
  • Chassis: 1-ton Ford Dana 60 front axle and Dana 60 rear axle, T-18 Ford 4-speed transmission, 205 transfer case.
  • Performance: 121 rear wheel horsepower
Cummins Conversions -

Denny bought his FJ brand new in late 1968, and has competed in off-road events nearly every year since - accumulating an amazing 269 first place trophies along the way. The 5.9L Cummins was tuned for low-speed off-road performance and rock crawling, not necessarily for dyno events.

Cummins Conversions -

A slew of Autometer gauges mounted in a custom aluminum panel keeps Denny aware of what's happening under the hood.

Cummins Conversions -
  • Owner: Darin King
  • Truck: 1985 (mostly) Dodge Custom Crew Cab Long Box 4x4
  • Engine: 1993 Dodge 5.9L 12-valve Cummins
  • Fuel Injection System: BOSCH VE rotary/mechanical fuel injection pump
  • Chassis: 1993 Chassis and drivetrain components
  • Performance: 200 rear wheel horsepower
Cummins Conversions -

Darin's truck is a custom creation that was still under construction when these photos were taken. Dodge never produced a crew cab long box, at least not since the 1980s, which is what Darin wanted. The multi-colored truck shown here was assembled from several period examples, bringing together just the right combination of straight sheet metal that created a one-off that draws attention.

Diesel conversions done right can be a worthwhile endeavor. Whether your engine choice involves a GM, Dodge or Ford diesel, knowing what's possible can sometimes help us to begin the adventure. If you have a diesel conversion story to tell and would like to see your vehicle get the respect it deserves, let us know. Stay tuned, lots more info coming.

The Diesel Page

Duramax Diesel Conversion Guide Forums
What's New: | Feature Articles: | Product Reviews: | Member's Area:
Join Us: | Duramax Diesel Page: | Advertisers: | Classified Ads: | Books:

Send e-mail to:
Copyright © 2019 by The Diesel Page

Copyright © 2013 by