351 cleveland getting hot please help

[69me 10]

hello, I have a 1969 fastback with a 1972 351 Cleveland that has been getting a little too hot for my taste. it climbing over 200 at highway speeds. I didn't notice this problem when I first got the car. I may have been distracted with all the other little problems. the car currently has an hei type distributor, which I tried to change to the msd system that was in the trunk of the car along with the a/c and power steering parts that I have put them back on the car.i have also tried two different electric fans, a zirgo 3000cfm and a Taurus fan which is a pretty powerful unit. I have replaced the themostat with a Cleveland correct 180 t stat. ive also tried playing with the timing a little. im not sure what all has been done the the engine other than a cam swap intake and carb and headers. im hoping I don't have to go back to the stock fan, but it is an easy, enexpensive trial. I also noticed the engine dies down a little when the fan comes on, not sure if it is taking power away from the fuel pump or distributor or both

[jandj1970 13]

Thermo fans draw a lot of amps when they kick, do you know what amp alternator you have on your car? What's your radiator like, your temp gauge its it factory or aftermarket?

When you put the correct thermostat in do you also have the restrictor plate under the thermostat.

Are you shore you bought the right thermostat for the cleveland? Hows your water pump.

[jandj1970 13]

I forgot to mention, does your bottom radiator hose have the spring in it. If it doesn't that could be restricting flow at highway speeds.

[jmlay 80]

The 351C usEs a unique thermostat, ensure you have the correct one. Here is a recent thread on overheating issues with a 351C.:

 

http://www.1969stang.com/mustang/forum/showthread.php?t=13957&highlight=351c+overheating

[69me 10]

the alternator is brand new 100 amp. the thermo stat is correct I verified part number. and made sure the restrictor plate was there. the radiator is what looks to be factory(car came with a Windsor). lower radiator hose does not have spring in it, but does not seem to be collapsing. it also gets hot sitting at idle with fan on

[jandj1970 13]

Are you running electric fuel pump and dizzy? If you are I don't think the 100 amp alternator is up to the task. Have you bleed the air from your cooling system properly? IF your radiator is orginal I would replace it with a quality one along with a new water pump.

Can you get your hands on a thermo gun to verify its actually running hot.

[danno 128]

I am not sure, but I have heard that when you are on the road doing 60mph, the fan is doing very little. Most of the wind comes from the your motion. But you said it could be the original radiator, and that is a big clue. Those get plugged up with gunk and stuff. It it is original, at a minimum I would take it out, and take it to a good radiator shop where they can flush it and check for the proper flow rate.