[DAVID GAGNARD]

El;

I've used thermostats just like the ones in your photo.. While the gold one on the left may be the best flowing, I've had the worst luck with them.... I've had the best luck with the el-cheapo Auto Zone ones in 180 degress like the 2 on the right, I would also suggest 4, 1/8 holes in the thermostat flange......I always test them before installing them in water just as you did and let them cycle 3 or 4 times just to be sure..... had one last year that opened and closed perfectly the first time and on the second cycle as it was closing it closed "off center" and was stuck at about 25% open...

Was has me puzzled is the "boiling" back of the water in the expansion tank, that ain't good........

On my Mustang, I run the 180 thermostat with 4, 1/8 holes and an 17inch diameter electric fan (curved blade, they work better than straight blades I've found) with a manual on/off switch....On the highway I never have to turn on the fan, the car will run 180 degrees as long as I'm going 40 mph or more no matter the outside temp. In city driving I leave the fan on and it may creep up to 185 in prolonged stop/go traffic, but that's about it....

I'm running a 351-W and a larger radiator than you have,so we're not comparing apples to apples here....

My radiator and motor combined hold somewhere between 3 and 4 gallons, I think.....

I would try the water restictor instead of a thermostat, just to eliminate the thermostat, it's a quick and easy change, as well as a smaller water pump pulley or larger crank pulley....

I'm like vettestr, I'd like to see some pics of the front of the car as well as from inside looking at the back of the radiator.....

Something just doesn't add up.....Your set-up should work without any problems as I've seen smaller radiators/fans and the cars ran o-k temp. wise...........

I don't recall seeing it, but are you running a puller or pusher fan??both????Pusher fans in the front may look peroid correct, but actually can restrict airflow,a puller, shrouded fan on the rear are the most efficent and when off, will not restrict airflow nearly as much as a front mounted pusher fan........

David