Is it the sticker on the air cleaner????
- I look at what the factory was targeting, and the intent when creating a particular "engine package". I really don't believe HP is the deciding factor. Although the 273 "commando" wasn't at the mountain top in HP, it was designed to compete in the Pony car war and the autocross races. That makes it a "performance engine".
- Also, many of the "performance engines" will be surrounded by support to the car. Such as the rear end, larger brakes, sway bars, or other such features.
I'm not familiar. What was the rated hp increase of the commando over the 2bbl 273?
Competing with the mustang at the time
2bbl 289: obvious answer-no
4bbl 225hp 289: meh. Not hp imo.
271hp 289: now thats a performance engine.