Yeah you should not let it idle, thats the important thing, the cam is a lot less stress free at 3k than jumping about at idle, plus the oil pressure is higher. Kent recomend a static running in procedure, cant remember the exact sequence, but it was like "hold at 2000 for five mins, 3000 for another five, then 2000 again, then another similar sequence, never stopping the engine or letting it idle. TBH im not sure its all entirely nesesary as im sure ford never ran in thier stuff.