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 ...

The rocker arm employs the use of a fulcrum or pivot to increase the cam lift by a given ratio. That increase in lift is the result of moving the pushrod pivot point closer to the fulcrum. That ...

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 ...