I have owned many GM vehicles in my 27 years. I have owned a 1983 Z28, 1984 K5 Blazer, 1985 Cavalier, 1980 Delta 88, 1981 Olds 98, 1991 Chevy Truck, 1998 Olds Intrigue, 1999 Cavalier, 2000 GMC Denali, and 2000 Chevy 3/4 ton truck. I have had great luck with all. I sold my 1991 truck three years ago with 160,000 miles on it, and the guy still drives it daily. I typically drive the hell out of a vehicle. I believe in using every horse power possible, and I still have had excellent luck with GM vehicles. I do believe that the mid-1980's vehicles are of good quality, but their horse power and fuel mileage absolutely suck. My Z28 was rated at 195 hp and only got 16 MPG!
Phil