Just got my 1970 Duster 340 the other day. Had to drive it on the highway about 20 miles each way today, and it ran very hot (one line below H on gauge). Outside temp was around 90, and on a wide-open highway cruising at 65-70. I never had an electric fan, but do know a lot of cars use them down here. It is at least 90 every day from late May through early Sept. My '70 Roadrunner I just sold never got hot, even on the hottest day, but it had the 26" fan and shroud. The Duster has no shroud. My radiator is 22" wide and I would appreciate comments about the benefits of changing fans. Also, which brand is good, I don't need the "best". Also, what is the price range I can expect to pay, and what size fan is recommended? Here is my setup: The car is recently totally restored, new water pump, radiator done, etc. It did come out of Canada, so I will check which spark plugs are in it as suggested below. If I decide to change plugs, what plugs are recommended (brand,size and gap). This is a stock rebuilt 340.