Pilot holes are required. All these rated lag type devices have a recommended hole size, but I usually just eye ball it and use a bit two or three sizes smaller than the shank (non threaded part). Start too small, try to thread it, and if it feels like you're about to twist it too hard, go a little bigger.
The real problem is making sure you use the right type of eye-let. If it is not shouldered, you can not side load it. If you do, it will either break or pull out.
That sounds like something that would be included in a booklet that comes with the DVD Bob mentioned earlier in the thread
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