Install shim or not for tubular upper arms

This is probably going to be a stupid but I'm going to ask it anyway. I'm in the tear down process of replacing upper and lower control to the CPP ones. While removing the upper control a shim fell out from behind the control arm (front bolt on both arms). ? should i put the shim back in with the new upper control arms? I think i should but just wanted to ask. Thanks

If you shim the front bolt of the UCA you will be adding caster. I shimmed mine to center the wheel in the wheelwell better. When you adjust caster it will move the wheel forward and backward within the wheelwell. If you are happy with your previous wheel location and are using the same alignment specs I suggest you re-install the shims. However, you will need longer bolts than the ones provided by CPP.