Back then, there were 5 grades of full size Buicks. Base was the LeSabre. One up was the LeSabre Custom/Limited (depending on the year), and both had 3 venti-ports. Above that was the Electra series. Base was the Electra 225, with the one up being the Limited (which did not actually say Electra anywhere on it), and the top line being the Electra Park Avenue (again,without actually saying Electra on it). All 3 Electra models had 4 venti-ports and a slightly different front face. For 77/78, the Electra models had the separate turn signal lenses of your car. The LeSabre had the grill texture run over the turn signals. Hope that helps clear up what model is which, and that is it is slightly clearer than mud.