On the Edelbrock Victors I run, Hughes 1.6 rockers measure close to 1.60 when using a checking spring. When measured with the 600+ lb open-load roller spring, all the deflection in the valve train drops the net ratio to 1.54-1.55.

I checked out some Hughes 1.7 at the same time, although I use their 1.6 rockers. Unloaded they were in the high 1.6s, but against the roller spring they dropped closer to 1.60, losing more ratio than the 1.6 rockers. I suspect this may be the result of Hughes changing their design to include a "trench" down the backbone of the rocker body. I have the early style without the "trench" and believe it's stronger (less flexible) under a load.

FWIW, I passed on my measurements to Hughes and suggested they still offer the early design as a "heavy duty" option, but never saw any response from them.

One last comment is that Hughes rockers have a regressive ratio curve, meaning they start out much higher than the advertised ratio early in the lift, then the ratio drops off as the lift increases. Think of it as starting out at 1.7 off the seat and ending up at 1.5 near peak lift, so it averages out to 1.6 overall. Some rockers are linear, some are progressive, and some are regressive.

All this ratio stuff also depends on the shaft location with respect to the valve tip, the relative length of the adjuster screw, the angle of the adjuster screw, the rocker body fulcrum length, etc. Fun, fun, fun...