I've posted before some of the issues I've had with the cooling system on my 67. Last summer I thought I had it all figured out with a high flow waterpump, OEM a/c fan with clutch, modified fan shroud to fit my aluminun radiator and 180 degree thermostat. Worked very well all summer for keeping the engine running cool, but I did notice the temp was actually falling with higher speeds. Late last fall we went to a weekend long car show up in Crosslake, MN, and as luck would have it it rained like crazy on the trip home. It was also pretty cold out. Well the engine never got above about 130 degrees all the way back, about 190 miles. I figured the thermostat must be faulty, so this spring I decided to replace it with a 192 degree OEM thermostat. I'm a firm believer that engines run best at those recommended temps. So yesterday I drain the radiator and pull off the thermostat housing, and what do I find? I had installed the thermostat backwards! I still can't believe it. I've replaced probably 20 or 30 thermostats in my lifetime and I hope this is the first (and only) time I've done it wrong. I put the 192 in correctly and after 2 test drives I think I've finally got it. It runs right at 192 no matter what speed I'm driving. I'm guessing my main problem before was poor flow from the original waterpump, but I can't be sure cuz I changed too many things at the same time. Oh well, it's fixed now and I don't need those ugly electric fans any more.