The 880 was a hack job similar to the Demon. While the Demon was a Duster with a Dart front clip (note mismatched wheel well openings), the 880 was a 61 Chrysler with a Dodge Phoenix nose. Produced from 62-65, the best sales year was 1964 with 31,800 of them sold. Most were equipped with a 361, 2 bbl. It was rushed into production after Chrysler learned that the shrunken Chebby was not a shrunken Impala/Belaire but the Deuce. Chevy for its part came up with the Chevy II to replace the Corvair which was not selling well.
FWIW: Rumor and unconfirmed. The reason 1962 Dodge 440/Polara and Plymouth Fury looked a little strange is that they were put through a last minute downsize to meet the unexpected Chevy. The 62's were supposed to be downsized anyway, but when the rumor of the shrunken Chevy came to light, Exner and team tried to beat Chevy at its own game. The debacle put Exner out of a job, not helped by the ugly 60 & 61 models.