What transmission has overdrive does a 1988 chevy van 20 have?

The 1988 Chevy Van 20 typically comes equipped with a Turbo Hydra-Matic 400 or a 700R4 transmission, both of which feature overdrive capabilities. The 700R4, a more common option for improved fuel efficiency, has a 4th gear overdrive ratio of approximately 0.70:1. This allows for lower engine RPMs at highway speeds, enhancing fuel economy and reducing engine wear.