Hey guys I have a 87 cutlass ciera brougham with a 3.8 and 4 speed transmission. I need to replace my cv halfshafts but i don't know if my outboard shaft is a 20mm or a 24mm how can I tell this? Also I am doing my brakes and the parts store want to know if I have heavy duty brakes or light duty brakes how can I tell on this? Any insite would be great thanks guys. I didn't know these cars had so many different options.