Question about yeast starters

Hi, everyone. I plan on brewing this weekend. I got an extract kit of Rogue Dead Guy Ale clone from Austin Homebrew Supply, with a Wyeast Activator Pacman Ale yeast. Being that the OG of this brew is pretty high (1.064) I thought this would be a good opportunity to try a yeast starter for this brew.

I have an erlenmyer (sp?) flask, some light DME, rubber stopper, airlock, etc. for the starter. The process of making the starter is pretty clear to me. My main concerns are what's going to happen when a pitch 5 times the viable yeast cells that I have previously.

How vigorous will this ferment get? Right now, I do primary in the 7 gallon plastic "Ale Pale". Is this ferment going to overflow? If so, how do I set up a blowoff tube with a bucket? Would going to LHBS for a 6.5 gal carboy be the better bet here? Maybe the 7 gallon bucket has enough space to withstand the extra foam?

Any input would be most appreciated!

pitching that much doesnt mean you will have a overflow. you will however see a lag time of only about 5 hours or so.

I pitch a starter everytime (ok, ok well almost everytime) and i see the same amount of krausen as I do with pitching a non starter.