Spedometer and tach gage failures

The spedometer and tach on my car–2005 Chevy Cavalier–have stopped providing accurate info. Approx 3 years ago I hit a deer at 65mph. About 2-3 months after I got my car out of the body shop I started seeing intermitten hanging at 65mph. After a year it failed completely. Last August, during the Texas heat wave the tach started flaking out. Now it will drop off intermittenly also. A mechcanic has tested the sensors and tells me the sensors are working fine. The cruise control works and the trip/odometer works as well. Will after market gages work?? or do I need to replace the entire instrument cluster??

I’d look for bad electrical connections, including grounds, before replacing the gauges.

After market gauges? You won’t know whether they’ll work or not until after you’ve spent the money and installed them.

If it comes down to replacing the gauges, I’d look in a junk yard first.