A new 312-cid "Thunderbird" device with 215/225 horsepower was ­optional throughout the board, and a midrange 292-cid V-8 presented two hundred horsepower. A common suspension and forged-iron six -- mainly a 170-cid unit of 101 horsepower -- definitely looked uninteresting subsequent to Corvair engineering, but made for pleasant, roomy small vehicles that rode well and shipped 20-25 mpg.