BHO purging setup

Would a 1 gallon dessicator, and 3cfm single stage pump be good enough to purge around 7G of oil.

I just want to make sure it is strong enough to reach 30hg for a full vac.

And Also big enough to purge that much at once.

Here is the one I'm looking at:

http://www.amazon.com/gp/aw/d/B00NQ...SY340_QL65&keywords=vac+it+pro+vacuum+chamber

you want a dual stage pump

I was told a dual stage pump is more than needed, do you know what the pump I have above could pull?