I don't trust the Tachometer on my boat, and am thinking of replacing it. I have a 1977 85HP Evinrude.<br /><br />My question to those who know more than me is: What is the best Tachometer to use? Should I pony up for a NOS OMC unit on Ebay, or should I go with something in Overtons?<br /><br />Similarly, what is the best Speedometer? I probably ought to replace it as well....I'm not sure how old the one on the boat is.<br /><br />Joe