One of the most common valvetrain upgrades for pushrod-style engines is roller rocker arms, which are often said to increase horsepower through reducing friction. But is it true? You’ll find out on ...

It's no big revelation that high-lift rocker arms (those with a greater multiplication ratio than stock rocker arms) generally increase the performance of an engine without necessitating a camshaft ...

In the 1980s General Motors shifted away from small holes in the cylinder head and pushrod guide plates instead to what they refer to as “guided” rocker arms. These stamped rocker arms use two small ...

For racers, the most pressing questions we ponder late at night aren't about the meaning of life, the true meaning of beauty, or other such silliness. Yes, those things have their place, but we all ...