Great tips! Thanks for the feedback and advice. I had not thought of the boil off difference and that makes sense; I'm sure I would have gone with percentage rather than volume.
I only brew ten gallon batches, and as most recipes are written for five, I simply double everything. However, The local brew-pub did like one of my recipes, and to scale it up to the four bbl ssytem did take some tweaking. Considering efficiency differences and such. Beersmith made fairly easy though. change the % efficiency, then start tweaking grains and hops to get back to your iriginal IBU, and OG targets.
He went through the eight kegs pretty quick.
I'm gonna have my black IPA on tap there this fall.