65 cuda 318 radiator question

Might just be some crud in there. You could try poking a piece of wire inside. Probably needs to be something flexible because it kind of needs to turn a corner. You might want to go to a NAPA store or someplace & look at a replacement petcock (that's what they're called) to see how it works. Then you'll know what you're trying to accomplish, but it's pretty straight forward. (turn a corner...straight forward....Does that make sense??? :scratch:)