Is it a Mitsubishi 49.5 hp diesel like used in the GA-500 tractors?
https://www.manytractors.com/farm-tractor/mitsubishi/modelsThe Mitsu “forklift diesel” was used in late 1970s Dodge pickups with manual transmissions,
and my fuzzy memory that it was also used in Chrysler South American assembled cars
wiki
The 1978 models also saw the introduction of the first diesel powered Dodge pickup truck. Available as an economy choice in light-duty trucks and B-series vans was Mitsubishi's 6DR5 4.0 L inline six-cylinder naturally-aspirated diesel, rated at 105 hp (78 kW) at 3500 rpm, and ~230 N·m (~169 lb·ft) at 2200 rpm. The diesel used standard Dodge manual and automatic transmissions via specially made adapter plate which had the LA V8 bolt pattern. This rare factory option, VIN code H, was the result of fuel crisis and the collaboration of Chrysler and Mitsubishi.[9] The engine, while being trustworthy and having far better economy than any other engine in the Dodge lineup at the time, suffered from low power output and was considered to be underpowered by American standards, even though it was previously used in the Japanese 3.5-ton cab-over Mitsubishi T44 Jupiter Truck and in industrial applications. Because of the low sales, it was phased out quickly, and as a result, it became practically a single-year specialty.
