I have a Futaba 3-Ch receiver. Don't recall the model number but receivers don't draw much current by themselves. I have a 5945MG and a Mamba Max ESC. I think the BEC Mike sent me has too little current capacity. This one has half that of the UBEC. I give Mike a call.
It might work. The peaks were at 2.4A, but the average was at 0.6A. If you use a capacitor on the UBEC, it will really help absorb some of those current transients. A value from 1,000uF to 4,700uF should do nicely. The majority of the current draw is when steering under heavy load. To do this, I had the truck sitting motionless and then manually held the tires somewhat firmly.