Im not sure what temp thermostat is in my engine right now but i never seem to warm up that much. The needle only gets up to the n on normal at the best. What is the right temp for a 351 to run at in the winter and in summer?

 

Every stock ford temp guage has run around the N in normal. 195 degree is stock, I have a 180 in my truck. I definitely wouldn't go any lower than 180.

 

Yeah, stock is 195 for emmisions reasons. I dropped mine to 180 as well to prevent overheating while towing - that 105 degree day towing up those steep hills just about did me in. I had to turn the heat on...(oops, rambling again.)

If I were you, I'd first put a peice of cardboard over the radiator to see if the gauge reads higher than N (love those informative gauges...). If so, the thermostat could be stuck open. If someone else owned this, they might have put a 'fail safe' in that sticks open when it fails, rather than the traditional type that stick closed.

Next, check to make sure the upper radiator hose doesn't get warm before it should. I'd just start it up cold and check that upper hose temp with your hand. It shouldn't get warm until the coolants heated up to 195 degrees(or 'N' on the gauge, I guess).

Tough to tell, but normal idling shouldn't get it there. You may want to rev it a bit to get it warm while holding the hose. You should feel a sudden temp surge in the hose as the thermostat opens.

If it's just gradual, pull it and boil it. Check the opening with a meat thermometer. Then replace it with a new one. Good luck.