refile labor in perm and keep the old priority date?

I am exploring options to convert my EB3 to EB2. I read something about get I40 use the old priorityy date and then get a new Labor in EB2 and still keep the old priority date. Does anyone knows anything about this? Or you have to give up your old priority date?

Is there any EB3 here still waiting. Is there any hope? I haven't look at the history of the EB3 priority date, what's it in 2006 and 2005 for EB3? Appreciate your input.