Painless Performance now has harnesses available for the 24-valve Cummins inline-six that was put in Dodge trucks from '03-'07. If you can manage to snag one those engines and a few key componants from the donor truck, with this harness, your swap is almost half done.
Contact: 817/244-6212, painlessperformance.com
If your concern with bolting up a transmission you already have or can readily find is the only thing stopping you from going to diesel then wait no longer. The 4L80E, 700R4, Allison, ZF6, Muncie, and C6 are but a few of the transmissions that you can bolt up using adapters from this company. It also has custom starters to get that diesel engine going.
Contact: 318/742-7754,transmissioncenter.org
Looking to save a few bucks by snagging a remanufactured engine? Power Pro remanufactures all the major diesel engines and can ship direct to your door. The stock the company has is amazing. However, you better have a core to supply them with or your reasonably priced deal goes up the scale a bit.
Contact: 888/608-4890,powerpro200.com
Don't know where to get that longedfor diesel engine? Whether it is a Ford, Cummins, Navistar, Detroit Diesel, New Holland, or Caterpillar engine you are looking for, Rhino Engines can supply your diesel swap project with the torque monster you need.
Contact: 800/454-8130,rhinoengines.com