Stock 302s with different horse power?

[Shortstop87]

Noticed the 302s during the bronco years have different horse power for the 302, does anyone know if this is actually correct or just error?

This was pulled from chiton repair Manuel for the bronco

 

[Ovalis]

The big change that happened in 1972 was when they changed from gross HP to net HP.

 

[SHX669]

What Ovalis ^^^ said

 

[toddz69]

And the 1977 era numbers were a little higher because the cylinder head combustion chambers were slightly different. I'm pretty sure the numbers for 1974/1975 (1975 in particular) are wrong in that chart. 1975 was the nadir of the 302 output in the Broncos with a rated output in the 120s range.

Todd Z.

 

[spap]

I forgot about the gross to net but also snag controls especially in 1975 and later
Crazy a 5.0 302 had less hp than a 2.5 liter escape

 

[thegreatjustino]

The change from gross numbers to net plus the ever restricting emissions. Look at the drop in Mustang HP numbers from the late 60s to the early 70s.

Amazing what the EPA did to performance numbers.

 

[blubuckaroo]

And the 1977 era numbers were a little higher because the cylinder head combustion chambers were slightly different. I'm pretty sure the numbers for 1974/1975 (1975 in particular) are wrong in that chart. 1975 was the nadir of the 302 output in the Broncos with a rated output in the 120s range.

Todd Z.

Right. My '77 is a CA car. The 302 was rated at 127 horsepower.
Both the 302 and the 351W used the same poopy low compression head that year. Just changing the heads and cam woke it up substantially.