Can someone summarize the basic differences between the W114 and the W115 chassis? I know the 280 usually has 6-cyl engine and the 230 has 4-cyl engine. The 280 also has wooden dash and the 230 vinyl. But are there significant differences in the chassis, suspension etc.? Is the 230 a cheapened down version of the 280? I'm talking about the 1972-1976 models.