The rocker arm is a "see-saw"...the pivot and relationship between where the pushrod and the valve tip are located on the rocker and the pivot point at the rocker shaft determine the ratio, or multiplier for the lift from the cam lobe, and how the duration and cam events are perceived at the valve... (i.e. if the ratio is 1.5 at the rocker, the cam lobe at max height is .300 then 1.5 x .300 =.450 max lift at valve, if a set of longer rockers can be installed and setup properly then you can get more lift/and alter the perceived cam events a bit...so a set of RAS 1.6 rocker x our .300 lift cam would net a .480 lift)...all things not being 100% fair in the universe and how physics works, and mass production tolerances a couple things will happen...you may loose some lift due to the valve lash not being 100% perfect...also because our rockers were stamped mass production units they are not 100% perfect and land in the 1.465 ratio range (On my hipo engines I've pulled several engine's worth of rockers and put together a set or two that were "close" and not all over the board cylinder to cylinder.)

There really isn't a set of 1.6 rockers for daily driving, they are also $$$ compared to other improvements that can be done to the engine (these are really key if drag racing or doing an all out engine that needs a little more than the standard tricks can't provide).

-D.Idiot