I have setup my share of 6 string guitars, but this is my first bass setup. its a 4 string ibanez sr600. picked it up used last week. ibanez with factory specs using .045-.105 strings says the neck relief should be between .3mm-.5mm at the 8th fret with the first fret fretted and fret at the body. it took about a half a turn to loosen the truss rod and get my feeler gauge for E about .457mm (.018in feeler). however the G is between .813mm and .889mm. ?!?! I have never seen that sort of variation. is this a bass thing? EDIT: I put the E to right about .3mm and the G is kissing the .65mm but clearing the .75mm gauge. it just seems excessive.