Hello,<br />I have a 22 ft. Sunrunner with a Mercruiser 5.7litre V8 engine with thuderbolt ignition. My tachometer is acting very erratic and I think I should replace it. I can't get one in the current dash due to shape...but I will mount it just above the dash. Does anyone know if I need a specific tach or will any tach do?<br />Thanks,<br />Adam