Yes you can use them with no problems. Now the older Futaba servos were not set up for a 1.5 millisecond neutral so, with neutral trim on the Xmter, the servos will not center in quite the same position as the later brands of servos do. Now, you can open up the servo case and rotate the motor a slight amount to get the servos to center the same as the later issues do. That is not necessary though, you can just go ahead and use them as is. If the servo horns are the old square hole, you can not reposition the arm to correct this offset. If it has the odd number of splines on the servo output shaft, then you can just rotate the arm on the shaft by a spline or two to correct that.