Hi all, I've got a bit of an action issue with my Cort C4Z. The action is a bit high for my liking-about 3/16 at the 17th fret from fret top to bottom of E string. Most setup guides say 6 or 7/64 is good here. Problem is my saddles are as low as they can go on E and G strings. Neck relief is about perfect: 1-1.5 business card thick when strings are held to straight edge at 1st fret and where neck meets body. Truss adjustments only get buzzy when tightened so my neck setup is as good as I can get it. The only thing I've not done is shim the neck in the pocket. My question: is this an acceptable fix and does it negatively affect the tone of the guitar? (ie: take away from neck/body mating for sound quality). Thanks. Also, if it's ok to shim, what should I use? Bus. card-piece of wood....? Thanks.