No, a 1972 Chevrolet 1-2 ton 4x4 truck did not offer the 396 cubic inch Big Block engine as a factory option. The largest engine typically available in those trucks was a 454 cubic inch Big Block, but even that was not standard across all models and trim levels. The most common engines were smaller displacement V8s and inline-6s.
While it's *possible* someone swapped in a 396 later, it wouldn't have been a factory configuration.
