Okay here's the deal.

The orange T-shirt crowd will tell you the've done it without issue.

Bax (Futaba service in the USA at Hobby Services) will tell you the buss in those rx's is only good to 8 amps. He's also noted in a couple of threads on the Futaba support forum here that he thinks the 35 amp continous 50 amp burst capability of the 9 channel and above Spektrum/JR 2.4GHz rx's is a lie....[X(]

You can use a rule of thumb that 100oz. of torque will require 1 amp of power and that will be very close to actual servo specs. Be aware that if a servo binds up or something it can exceed that current draw by 50%.

Next issue is that even the best servo leads with at least 22g. wire and gold plated connectors can only handle about 4 amps continous and burst to 6 amps for short periods with cheap leads or connectors only supporting about half that load, the 7950 can pull 4 amps all by itself and you've used half the capacity of the rx buss with one servo....[X(]

I'd put a PE in it but that's my personal opinion....