In 1p config you will be stressing them. I found the packs got pretty hot in 1p on my LS10 also. I was running 4s1p but have since swithched to 3s2p and get almost identical performance, but much better run time. The voltage drop on the a123 cells in 1p was really huge. the 13.2v 4s pack was dropping down to 8.9v (2.23v/cell
)at the current peaks of 80amps and the packs got pretty hot. Hotter than I liked anyway. Thats only 35c and they are rated for 70C peaks so I think that the a123 specs are probably a little optomistic for real world use. 3s2p gives me almost exactly the same minimum voltage at the current peak, but that is on a 3 cell pack so the cells appear to be handleing the load much better.
2P should fix your issue.