Tribute S-500 neck shim

I have a tribute S-500 and when setting my action I have the string saddle (I think that is what it is called) down as far as it can go for both my high E and B string and they are still 7/64 from frets at the 12 and 14 fret. I have done investigation and tried things that made sense to try and still no luck. I am left with putting a shim in the neck to raise it up. I do have some questions.

What should I use for a shim. I’ve read people using picks, credit cards, copper.?

How thick should the shim be, I need the string to be 4/64 closer does that mean a 4/64 shim?

I’ve read people saying you lose sustain when you shim because of a loss of contact between the neck and body?

I believe the shim should go up by the pickups but how far back should it go away from the pickups 1/4” or 1/2“?

Thanks in advance for any advice.

Jeff

Jeff, Yes a shim will correct the issue. I use brass as it doesn't compress like plastic or cardboard and is stable. I would cut a .010 shim and try that first. If that doesn't get the saddles off the bridge, add another. I place the shim in this case between the neck bolts closest to the neck pickup and the neck pocket edge. I also trim it to fit the cavity nicely. I do not think that it has a noticeable effect on sustain. You actually get more direct contact then you would with a micro tilt. I have done this to many guitars with total success.-- Darwin