47-55.1 radiator install

[dsraven]

also check the cap to see if it has 2 gaskets. one to seal the rad and this one has the spring loaded feature. the other to seal the larger part of the cap to the larger part of the rad opening. this is what makes a closed system where the contents of the reservoiror or overflow bottle can be drawn back into the rad when the engine cools down, creating a negative pressure inside the rad. the old fashioned top tank rads didn't have the gasket right under the top of the cap so the overflow simply dumped onto the ground. the system needed to be checked and topped up more often to ensure the rad still had sufficient coolant level, especially after some hot running operations. usually guys would overfill the rad and it would puke out what it didn't need. those were engineered systems with a slight safety built in, fans that ran on a belt with no clutch fan system, no a/c condensor adding heat to the area, no trans cooler or p/s cooler adding heat, etc etc. nowadays, with backyard builds especially, it is best to have a rad that is too big than one that is possibly too small when running all the other coolers etc. a closed system with a good sized overflow tank is a great idea. just my opinion.