What size engine is in the 1975 Chevy C10?
The 1975 Chevy C10 offered several engine sizes rather than a single specification. The most common engine was the 350 cubic inch V8, with additional options including a 250 cubic inch inline-six and a 400 cubic inch V8; some heavy-duty configurations could also be equipped with a 454 cubic inch big-block.
Engine options for the 1975 C10
The following engines were available across C10 models, varying by trim and chassis. The list highlights the main powerplants GM offered that year.
- 250 cubic inch inline-six (4.1 L)
- 350 cubic inch V8 (5.7 L)
- 400 cubic inch V8 (6.6 L)
- 454 cubic inch big-block V8 (7.4 L) available on some heavy-duty configurations
Note: Availability depended on the specific C10 variant and dealership order. The 350 V8 was the most common engine in 1/2-ton C10 pickups, while the inline-six 250 offered a fuel-efficient alternative, and the 400 and 454 engines were selected for higher torque and payload capability on select builds.
Context and impact on performance
In the mid-1970s, GM offered a mix of smaller and larger powerplants to meet differing needs and the era’s emissions controls. The 350 V8 provided solid torque for daily driving, the 250 six delivered simplicity and economy, and the 400 V8—being larger—was aimed at heavier-duty use; the 454 was rarer and typically found on the more capable heavy-duty lines rather than the standard C10 lineup.
Common misconceptions and how to verify your model
Because engine choice varied with trim, options, and optional packages, the only way to confirm a specific truck’s engine is to check the build sheet (RPO codes) for that vehicle or inspect the engine block for the displacement stamp. If you’re evaluating a used C10, these identifiers are usually visible on the engine pad or in the glovebox/maintenance papers.
Summary
The 1975 Chevy C10 didn’t have a single engine size. The lineup commonly included the 250 cu in inline-six and the 350 cu in and 400 cu in small-block V8s, with the 454 cu in big-block offered on select heavy-duty configurations.
