THE BOLT-ON BUCKET SEAT SYSTEM ... These 1955-1956-1957 Chevrolet Bel Air to Impala Super Sport Conversion Bucket Seat Floor Brackets are a custom-fit part. This four-piece bracket set allows you to install 1962-1965 Impala SS Bucket Seats. The braces are made specifically to fit the contour of a 1955-1957 floor pan so you can bolt down the seats. The tracks are also able to be attached with minimal welding if desired. For those who don't like the modern bucket seats but want something more vintage, this is the perfect fit. Seat Tracks sold separately.