Maybe this will help you with your decision.
first minute of a run with 8s1p A123 in a 1:8 buggy/truggy hybrid
The battery pack was fully charged 5 weeks before i did this run. Peak voltage 27.88V, but it usually is higher (28.5V) when the pack comes fresh from the charger. After a minute voltage drops somewhat (25V) but while braking voltage may rise (+1V). After a run with 18-20A discharge on average, the average voltage is 23.8V (a bit lower then 3V per cell).
Seems a bit too risky for me. 7s A123 should be on the safer side.