The increased rocker ratio works like this.
The math:
.480 lift divided by the 1.5 rocker ratio = .320
.320 X 1.6 rocker ratio = .512
This .032 gain is small. But the higher lift is more than likely useable even on a stock head. Though there really isn't much of a reason to lift the valve past the heads abilty to flow air on the street level ride, the stock head should still do fine at this lift.
Now the new higher lift is also more accurate over the stamped rockers that normally fall under a ratio between 1.48-1.42.
The other thing the new rocker ratio does is rise the valve a tad bit sooner increasing the cam duration as seen at the valve. The increase is super small. 2*'s is the given increase.
To me, the use of a higher rocker ratio just simply gets back the missing advertised lift of the cam and a little tiny bit more. It is a known fact that you loose some lift due to the angles within the engine.
The thing you should look out for and prep for in the increased vale lift is clearances. At the piston to valve & spring bind.
Does it add HP & torque?
Yes, but I doubt the butt Dyno will notice.
Consider the use of 1.6 rockers as getting what you should have gotten at the valve in lift from the cam to start with. Not what you actually get, which would be less than what is advertised.
