Richard Holdener
March 1, 2010

Power Numbers
It looks like the Ford power ratings for the Hi-Po 289 were pretty accurate and, surprisingly enough, so were those given to the Shelby 289. We know Shelby is famous for the Cobra, but he wasn't above selling a little snake oil every now and then. The modifications performed on the Hi-Po 289 to transform it into a Shelby version (circa 1965) cooked as good as they looked. The combination of the aluminum intake manifold, Holley carb, and tri-Y headers were worth as much as 28 hp and 26 lb. ft. of torque over Ford's Hi-Po version. There are obviously more powerful modifications available for a small-block Ford, but the Shelby mods were certainly tried and true.

Hi-Po 289Shelby 289Gains
RPMHPTQHPTQHPTQ
26001212451322661121
2900136246147267921
32001592611742851524
35001852771982971320
38002072862213061420
41002242872403071620
44002402862593091923
47002532832773092426
50002622752873012526
53002692672962932726
56002722553002812826
59002732433012682825

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