wow,
gtsr515 is wrong for once
the 1.7 or 1.6 is a ratio. You multiply the lobe lift by this ratio to get total lift.
Lets take for example a B-303 (mainly because its the only cam that i know the lobe lift off the top of my head) it's lobe lift is .300" multiply by 1.6 and you get the advertised .480" total lift.
If you dont know the lobe lift of a particular cam, all you need to do is take a ratio of ratios, divide the new rocker ratio by the old, then multiply by the advertised total lift. if you have 1.7's with a B-303, then (1.7/1.6)x0.480 = 0.510"
in your case, (1.7/1.6)x0.542 = 0.575875" (so Skyman is right)
I sure hope you have some serious valve relief's in your pistons.
Also i agree that that is wayyy too much for stock heads, try to keep it around .500"