Yes, this certainly is possible, just as the previous poster has indicated. We have a client doing just this, manufacturing at one unit of measure and then selling at a smaller unit of measure. GP supports this, so long as FT3 = qty 3 of FT.
Only note: be careful on custom reporting. You'll always want to be sure of your calculations, and factor in the Qty in base unit of measure column (QTYBSUOM, I think). Multiply that times the QTY field to get the base units being sold. In your case, the base units could be EITHER FT or FT3. I would recommend FT, because if you use FT3 then then you're going to run into rounding issues on qty conversions, since you'll always be multiplying by .33333.
Ron Draganowski
Senior Solution Developer
Olsen Thielen Technologies, Inc.
rdrag@ottechnologies.com
www.ottechnologies.com
Find me on LinkedIn: http://www.linkedin.com/in/rondraganowski