Getting a 20 horsepower bump just by reducing valvetrain friction from the roller rockers might seem too good to be true. Spoiler alert — it is. That's because when rocker arms are replaced ...

Now consider an aftermarket roller rocker arm with a 1.6:1 ratio. That equates to 0.3 inches of camshaft lift multiplied by 1.6 equals 0.48 of valve lift, or the amount the valve opens into the ...

We used a set of Trick Flow 1.6:1 roller rocker arms, which increased the cam’s advertised lift (calculated with 1.5 rockers) from 0.550 inch to 0.586 inch.

Roller rocker arms actuate the valves, and hydraulic lash adjusters manage valve clearance automatically. The intake manifold on the 2GR-FE is made of plastic and includes a variable geometry design.

To enhance the performance of our 1965 Mustang’s 289-cube small-block, we recently added a Holley Sniper 2 fuel-injection setup and a Powermaster one-wire alternator. To increase its performance, we ...