Finally getting around to driving this pig after putting a tranny in and noticed temp guage keeps running up to hot. So I put a aftermarket one in to see where it's at and is running up to 230 degrees. No coolant in the oil and don't notice it burning any. Level has been staying the same. Figured I would start simple and cheap replacing thermostat and rad cap. Looking for input on temp of thermostat and psi of cap. I was thinking 195 degree thermostat and either 7 or 13 psi cap. What do you guya suggest. Thanks

 

If the radiator looks old and crusty, it might be the problem.

 

All the fins feel pretty evenly heated but I should pry give it a good flushing.

 

Is it doing it while pulling hard? driving around? idling? I'd replace the thermostat, or just remove it for a test run, and flush the rad as was suggested and see if it still gets hot, if it doesn't then it was the tstat, if it does then its deeper in somewhere.

When I bought my 66 with the 352 it would get hot like that in a hurry, ended up someone put the drivers side headgasket on wrong and blocked the cooling passage off at the rear of the block

 

just normal driving around idling seems it's ok.

 

These trucks came with a fan shroud, is it still in place?

 

yes it has it on still!

 

What conditions is it running hot, driving down the highway or stop and go? Does the lower rad hose have a spring in it? Both engine and radiator have to be clean of sediment, rust, and scale or there will be trouble. Use whatever thermostat temp is spec'd in the manual, there is NO benefit whatsoever to a lower temperature thermostat (and a lot of downside) and don't even think about removing it.

 

If it's an idle around work pickup, I kinda prefer 180 thermostats, if it's a driver 195 is good - seems like they will overshoot the thermostat if they get worked at all at low speeds, so it opens at 195, but with the low flow and not a pile of air through the radiator, they will peak up to 210-230 before they start cooling off, IME. On a driver, you have enough airflow from speed and RPM on the water pump to start cooling fast, so it's not an issue.

Pressure caps, I'm not sure what was stock, but that's what I usually stay with - figuring that lower might be easier on a questionable radiator and heater core. (on my own junk, that is)

A good flush on the radiator with cleaner seems to help on old Fords as much as anything - I don't know if the tubes are narrower than others, these just didn't have quite enough radiator, or what it is, but I've had several that had heating problems that ended up being a restricted radiator. You can't get the good ol' Permatex radiator flush anymore (that I've found), but I've used the Prestone stuff before and it seems to knock the slime out pretty well. Then "I" tend to use regular Lime-A-Way, Barkeeper's Friend, or any of those regular household calcium/hard water products and give it a good cycle, then a REALLY good flush. Some will say it's too harsh, bad for copper/aluminum/etc., and it probably is, but I figure if it will eat through the copper that fast, it must have been thin enough it was gonna start leaking pretty quick anyhow. There's also some commercial rust/scale remover products that work well, I had a friend that worked at a hottub/pool place for a while and they had some stuff that worked like a champ.

I've heard the argument that "new" gas with ethanol makes these heat more, too - and maybe it does, don't really know. If that's the case, they just flat don't have enough radiator - I've swapped in an E-Bay Champion on one with a slightly built 400 (deer antler - don't ask ) and it ran significantly cooler with the aftermarket aluminum. Food for thought.....

On Edit - I didn't see Tedster's post above - he's absolutely right, running them "cold" is a bad thing, I believe 180-185 was factory? I've run them without a thermostat for diagnostic reasons, but not something you want to do long-term -

 

The only way to flush the block thoroughly is to remove the pipe plugs.... one on each side under cylinders 3 and 7. About two inches above the pan rail.

If nothing comes out, poke the hole with a screwdriver and stand clear. Built up scale and sediment settles to the bottom galleys and there will be a torrent of muck coming out!

Flush til it runs clear. Then back flush it too by positioning the hose right up against the block hole. Then flush from the top again.