I think its around 10,000, with leaving the butt section on the crane. I usually put a 4 part in my 25 ton just so I can fine tune adjust it, as your putting it in and out.
So I'm lifting the dead section tip, and the two powered sections all together, leaving the bottom section in the crane.
I also measure from the tip to the tail of the sections before pulling them out, then you can drag out 2/3 of the boom before attaching the crane, measure in from the tip 1/2 of your overall measurement so you know center of gravity.
Mine is the 105' main, 4 section total boom. There are some 80' main only booms out there, I don't know which you have.