The curb weight of a 1994 Chevy G20 Van will vary depending on engine and transmission size. The weight can be anywhere from 6,000 to 6,600 pounds. Equipment inside the van cargo area is also a factor. Seats will weight more than cabinet panels.
I'm not sure what the weight of your van is (the door sticker will not be accurate because the van was modified after leaving the manufacturer) however I recommend stopping by your nearest truck stop. Most truck stops have CAT scales and they will weigh your van for 3 to 8 dollars.