I wouldn't worry about it. Just install your engine on the mounts and you'll be fine. But if you have to readjust later it's not a big deal. Threadlok isn't permenant, you can still remove, or loosen, the hardware if you need to adjust it later. That is the blue threadlok isn't permenant, which is what you should use. NEVER use red threadlok on anything on an RC because it is permenant and you won't get it apart again.

Ken