The 9551 is not discontinued, it is backordered. Should be in later this month. ALL Futaba servos will comfortably handle 6.6V. Initially when Futaba only offered 4.8 NiCD packs, they said 4.8 only, but they will comfortably run at 6.6. In fact, in my wife's Monolog, and the Vanquish I put together I ran them at 6.6 V regulated with a tech aero regulator. No problems at all.

S9551 link.

http://www3.towerhobbies.com/cgi-bin...&I=LXRWS8&P=ML



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