1961 Cadillac 4-Door Hardtop
While the 1961 Cadillac looked entirely different from its 1960 predecessor, it remained very similar mechanically. The biggest change was a new front frame, which lowered the tubular X-member chassis to give more seat height and head room.
The 1961 Cadillac engine was basically the 331-cid ohv V-8 of 1949 bored and stroked to 390 cubes. The 345-bhp Eldorado powerplant of 1959-1960, with three 2-barrel carburetors and dual exhausts, was no longer offered.
1961-1964 Cadillac Article here on How Stuff Works: