'65 Mustang Hi-po vs '65 Formula S

I agree with you autox, although I'm not exactly sure what your point is. To me, the respective hp ratings (as well as the difference in factory warranties) indicate that the 271 horsepower HiPo 289 and the 235 horsepower Commando 273 were not and were not intended to be comparable engines. More comparable to the HiPo 289 would be the D-Dart 273, which was rated at 275 hp.