I would never ever pick a cam by lift. That would be for someone I didn't like.
Crane advertises there rate right on the card itself along with the duration at .050.
Valve float is the valve springs inabilty to control the cam at any RPM. Of course, the limit of the spring will be when the valve floats and you'll know.
Valve float can happen at almost any RPM. Period.
Advertised by Crane is .004 while many common Comp cams are at .006. But that changes rapidly when you roll around the catolog for a bit.
It's on the cam card... right????
