Original sentence: They were delivered from 1979 to 1982, and had their engines changed to GTO Chopper from Cam Shaft in 1992-1995.They were delivered from 1982-1985 and also had their engines changed to GTO Chopper in 1992-1995
Edited sentence: They were delivered from 1979 to 1982, and had their traction systems changed to GTO Chopper from Cam Shaft in 1992-1995.They were delivered from 1982-1985 and also had their traction systems changed to GTO Chopper in 1992-1995