Sorry to post so many questions. We just got a 1980 27' and really love it. Though very well loved, it sat for a while before we got it, so we've had countless little problems, but we sail her almost every day and little by little she's coming around.My first question is about the temperature gauge. I posted about this on another forum a while ago, but that was before I had really figured out my situation. Mine doesn't work. I tried cleaning the sending unit, but no luck- the gauge is all full of rust and water. Eventually I'm going to get another one from an online dealer, but until then I want to use an aftermarket one I already have. My problem is that I can't get the sending unit of this one to fit into the existing sending unit hole. My new one, with a standard size insert, is just too long. Now I have found that this one will easily fit into the hole of the sacrificial anode (I have a renault 8hp). That would get me great access to water in the head. I have also thought about putting it into the oil fill hole or the front of the sump. It would take me all of ten minutes to do either of those options.Am I correct to assume that the water temp should be between 120 and 140? What would the ideal oil temp be if I go that route? Any suggestions? Generally I only use it to get out of port, but we want to do some more extended cruising this summer and I really want to make sure she's not running hot.