修改 CHEVROLET G20 Standard Passenger Van

示范	生產日期	動力方面，KWT	動力HP	卷立方厘米	建築類型
CHEVR G20 Standard Passenger Van 4.8	09.1974 - 12.1978	89	121	4785	Bus
CHEVR G20 Standard Passenger Van 5.7	09.1976 - 12.1984	123	167	5733	Bus
CHEVR G20 Standard Passenger Van 4.1	09.1977 - 12.1984	86	117	4097	Bus