While marketed as a response to the first-generation Chrysler minivans, GM selected a rear-wheel drive layout, sizing the Astro and Safari closely to the short-wheelbase Chevrolet G10 van.

Similar to the Ford Aerostar, to reduce production costs, GM adapted light-truck powertrain components; engines and transmissions were sourced from the Chevrolet S-10, allowing for a towing capacity of up to 5,500 lb (2,500 kg).

For the M-van, the front suspension shared most components with the GM B-body station wagon (Chevrolet Caprice, Oldsmobile Custom Cruiser and larger variants of the Pontiac Safari and Buick Estate Wagon) with a leaf-spring rear suspension.

The lower ball joints were larger than their B-body counterparts (similar to the 1977–96 Cadillac D platform vehicles; e.g., Fleetwood limousines).

These ball joints were later used in the final Chevrolet Caprice 9C1 (police package) cars manufactured in 1995 and 1996.

As with many other 1993 model year GM vehicles, Scotchgard fabric protection also became a standard feature on Astro vans equipped with cloth seats.

The Astro and Safari also received center high mount stop lamps for 1994, which had been mandated on light trucks for the model year.

For 1995, the model was facelifted with an extended nose that resembled the then-new full-size Express vans; while the original rectangular sealed-beam headlights were retained for use on lower trim levels, higher-spec models now used horizontally-mounted rectangular headlights that had debuted on the full-size trucks in 1988, and would eventually appear on the smaller trucks in 1998.

For 2003, GM upgraded the chassis of both the Astro and Safari with certain suspension components, four-wheel disc brakes, and six-lug 16-inch wheels from the full-size Chevrolet and GMC half-ton pickup trucks.

The underbody of the test van buckled, pitching both front seats forward and shoving the crash dummy into the dashboard and steering wheel, resulting in a broken left leg, leading the institute to comment that "[t]he collapse of the occupant compartment left little survival space for the driver.

In side impacts, the Astro and Safari both received the highest, five-star rating in every year that the test was administered.