I have a 68 GTO hood tach in great shape but before I put it on Ebay I want to offer it here since it will work fine on a first generation Firebird. It has been professionally restored to stock specs and moisture sealed. It is the low profile style and has a steel blue background with 5100 redline. The gauge face and glass are perfect, don't be misled by the reflection on the glass in the photo. The case is in excellent shape too with no cracks but it does have some scratches and one small chip on the edge visible in the photo.
I put it on my Firebird this past weekend and it worked fine. Stock units this nice are getting harder to find. Comes with the wiring harness shown and template for installation. No gasket.