From the O-320 and IO-320 Series Lycoming operators manual:
Page 3-11:
All Models: Oil sump capacity 8 US quarts, Minimum safe quantity in sump 2 US quarts.
Page 3-12:
Consumption -A & -E series @150HP .67 qts/hr, @110HP ..37 qts/hr, @97HP .33 qts/hr
Consumption -B & -C series @160HP .72 qts/hr, @120HP ..4 qts/hr, @104HP .35 qts/hr
You sure would not find taking off with an engine at the minimum safe quantity plus consumption allowance. I'd be very concerned about overheating it....