Hi,
im new on this forum. I purchased 69 Dodge Polara 500 convertible and finally recevied it from the port. It runs nice, but when the engine is warmed up, some quite loud noise show up. When the engine is cold, i dont hear it. Its possible the sound is caused by water pump, which start work after the engine is warmed up? The noise sounds the same regardless the engine rev. Thanks for any hint

Typically a mechanically driven water pump is always working when the engine is on.

The type of noise your hearing would help get your problem narrowed down. A squealing sound could be a loose fan belt for example...

You might take off the WP fan belt after it's warmed up & see if that stops it. If so check if the belt is worn enough that its all the way down in the pulley groove. welcome here.