* TH700-R4: A 4-speed automatic transmission. This was very common.
* 4L60-E: A 4-speed automatic transmission, a later evolution of the TH700-R4. It's possible, but less likely than the TH700-R4 for a '93 model.
* Manual Transmissions: While less common, some G20s were available with manual transmissions (likely a 5-speed). The specific model number would depend on the engine and options.
To know for sure what transmission is in *your* specific 1993 Chevy G20, you need to check:
* The vehicle's identification plate (VIN): Decoding the VIN can reveal transmission details.
* The transmission itself: Look for a tag or casting number on the transmission case.
* The owner's manual: If you have the original manual, it should specify the transmission.
Without more information about your specific van, it's impossible to say definitively which transmission it has.