Hotrod magazine LA BUILD VERSUS LS

As we detailed in the first installment of this story, the engine was built for the inline-valve class in the competition, which had a displacement range of 370 to 490 ci. The other class was for canted valve/Hemi designs. And while those engines expectedly posted big peak numbers, Valley Performance’s output was right with them when it came to power-per-inch.

Our number was within 1 hp of the top Hemi engine,” says Barna. “So when it came to overall output, our LA really brought it home.”

The engine posted an average horsepower rating of 737 hp, which was about 4.5 percent lower than Valley Performance’s test pulls on a different dyno. Barna attributed the difference to a variety of contributors: a different dyno, different atmospheric conditions, a different altitude correction factor and more, but the bottom line is the engine squeezed out more per cube than its rivals.

“We believed a smaller engine would be more efficient when it comes to making the most average power per displacement, with less friction and more airflow per cubic inch,” he says. “The results speak for themselves.”