In short, a 1991 Ford F-350 could come with several engines depending on the build: gasoline V8s such as the 5.8-liter Windsor and the 7.5-liter (460), or diesel V8s like the 6.9-liter IDI and the 7.3-liter IDI.
The 1991 F-350 was part of Ford’s heavy-duty lineup and offered multiple powerplants across trims, cab/bed configurations, and markets. Gasoline engines came from Ford’s Windsor family, while the diesels were IDI designs marketed for towing and heavy payloads. Availability varied by configuration, and Turbocharged Power Stroke diesels would not appear until 1994.
Gasoline engines
These gasoline powerplants were commonly found in 1991 F-350 pickups and chassis-cab configurations.
- 5.8 L (351W) V8
- 7.5 L (460) V8
Gasoline options offered robust grunt for work duties, with different transmission and axle pairings to suit towing and payload needs.
Notes on gasoline engine options
The two gasoline engines provided substantial reliability for heavy-duty use, with availability varying by market and configuration.
Diesel engines
In 1991, Ford offered two IDI diesel options for the F-350: the 6.9-liter IDI and the 7.3-liter IDI, both indirect-injection designs and not turbocharged in that era.
- 6.9 L IDI V8
- 7.3 L IDI V8
Diesel models typically delivered high torque at low RPMs and were favored for towing and long-haul work, often paired with heavy-duty transmissions and axle gear ratios.
Notes on diesel engine options
The 7.3 L IDI would later evolve into the turbocharged Power Stroke in 1994, while the 6.9 L IDI remained a mainstay in earlier years before its phase-out.
Summary
For the 1991 Ford F-350, engine choices spanned two gasoline V8s and two IDI diesel V8s. The exact engine depended on trim, cab/bed configuration, and market. The Turbo Diesel era would begin a few years later with the Power Stroke introduced in 1994, changing the diesel lineup for Ford heavy-duty trucks.