* Transmission: The G20 came with several automatic and manual transmission options. The gear ratios within the transmission itself will vary depending on the specific transmission used.
* Rear Axle Ratio: This is the most significant factor affecting the overall gear ratio. Common rear axle ratios for a G20 of that era ranged from approximately 3.08 to 3.73, but could even be higher or lower depending on options selected when the van was new (tow package, etc.).
To find the exact gear ratio for *your* van:
1. Check the Vehicle's Data Plate: This sticker, usually located on the driver's side doorjamb or the glovebox, should specify the rear axle ratio (often denoted as something like "3.73").
2. Check the Transmission Identification: The transmission type is also usually found on the data plate or through the VIN. Once you know the transmission type (e.g., 4L60E, 700R4), you can search online for the specific gear ratios for that transmission.
3. Look for a Tag on the Differential: The rear differential itself may have a tag indicating the axle ratio. You'll need to access the differential (usually requires getting under the van).
Without knowing the specific transmission and axle ratio of your van, it's impossible to give you a definitive answer.
