Sun "Super tach 2" fits behind the OEM bezel just fine. print out a retro font label and your back in universal tach business. Then go out and get yourself an electronic ignition upgrade. I sold my tach and sender for $500 years ago on ebay! I paid $800 for the car! All this stuff in there is solid state, cant be that hard to desolder and test the usual suspects of capacitors and germanium transistors...