I'm full of useless car trivia from the 60s and 70s. Horsepower ratings were toyed with by all the big brands back then. Usually they would underate motors, for insurance purposes or, for factory race cars, to get an advantage in NHRA Stock and Super Stock racing. In the 1965 model year, Chevy introduced their new big block engine, the 396, in the Corvette, rated at 425HP, then later that year, they put the same motor in the Chevelle and rated it 375HP. Hmmmm. The GTOs, and 442s, seemed to have only about 20 HP difference between their standard engine and all their optional ones. Then in 1970 their engines grew to 455 cu.in. and still had almost the same ratings, even the Ram Air Pontiac and W Olds engines. Gee, better heads, 55 more cubes, better cam, no horsepower. Chrysler had their street Hemi rated at 425HP, and in 1968 produced factory race car Darts and Barracudas with almost none of the same engine parts, except maybe the block, still 425HP. Yeah, right. In 1968 Ford took their 428 T-bird engine, put it in Mustangs and Torinos, added big heads, better intake, more cam, bigger carb, called it the Cobra Jet, and had almost the same rating as the T-bird engine they started with. Chevy L-88 and ZL-1 427s were factory race engines and were rated at 5HP more than the regular solid cam 427 at 425HP. They actually made 500HP or more.
