I’m sure that there are roaming tribes that split their alliances to their favorite diesel trucks, but be fair: if it wasn’t for what happened when Dodge and Cummins paired off in 1989, diesel performance wouldn’t be anywhere near what it is today. Stuffing the 6BT into the Ram 350 showed many buyers who prior to had lived for the largest V8 gas engine available just what a good diesel engine could provide: all of the torque, better fuel economy, and that big-rig cachet that comes with an oil burner. It wasn’t the first time that Dodge flirted with a diesel-powered pickup, however…for 1978, Dodge took the Mitsubishi 6DR5 inline-six naturally aspirated diesel and offered it in Dodge trucks as an economy alternative. That effort failed on a massive scale, but the idea had been rooted in good intentions: think of it not as a Cummins, where the powerplant was meant to be a powerhouse, but more like what the modern EcoDiesel was supposed to be, a torquey economy mill, instead. 
Well, let’s talk about this 1976 Dodge D200 for a second. Yeah, that’s a Cummins emblem on the fender. And it wouldn’t be too farfetched to say that this is a frame-swapped setup, using a 1989-1993 Cummins frame and running gear with a 1976 body. But it’s not…instead, this is a slightly different engine swap, one that utilizes the 4BT four-cylinder variation of the B-series engine. Same Holset turbocharger setup, just two cylinders down compared to the big-brother 6BT, all wrapped up in a clean but aged older Dodge truck. Shifting gears is a Ford C6 automatic and a GearVendors unit, and once you fix whatever went wrong with the air conditioning system, you’ll have every working option, including cruise control, at your leisure. You’ll have useable diesel power but you’ll leave every coal-rolling fanboy wondering why it doesn’t sound like they were expecting it to.
eBay Link: 1976 Dodge D200
Nice looking truck. I love the old American stuff
The early 6BT OEM Dodges had a nasty habit of breaking the frame rails just behind the cab due to producing more torque than the frame was designed to accommodate. 4BT is a good choice here.