I have used the normal 4-40 or 2-56 rods for engine throttles forever. I mostly used a ball link on the throttle linkage on the carb. With 2.4, the concern isn't as great as it was with 72mhz. As recommended, just keep the receiver as far as possible from the ignition. 10 inches should be alright. If the spark plug caps have a spring inside, make sure that the spring stays inside the cap, should you remove the cap. Some how it helps to ground the plug. On first start up, do a range test and run the engine at full throttle during the range test. Do not move the controls and watch for glitching of the controls. If you are going to have any issues, it should show up there. Too many guys run at full throttle, wiggle the controls, and don't take the time to look for the glitching.
Best of luck!