I'm having a slight problem with my Read Custom that just came in. There is alot of relief in the neck, and while I'm going to let it adjust for atleast 24 hours, I was just checking to see what size allen wrench I'm going to need. The truss rod nut is smaller than what I'm used to seeing. I only have a metric set, but none of the sizes I have fit. Two wrenches that are even close to the size are either too small or too big. Could this be an SAE sized nut, in which case I'd have to get an SAE set of wrenches?