I have searched the archives , used the search engine and found some threads on what I was looking for , but not any help on finding my exact part I need. So I'm throwing it out there for all of you to maybe give me some guidance. I have an aftermarket polished radiator tank with a SMALL 16psi cap. My cap is not holding the pressure anymore. Lets the coolant leak out the overflow tube. I searched several companies websites , looking for the small cap and couldn't find one. Called a company and talked with a very knowledgible fella, thought we had the correct one I needed and ordered it, only to come in the wrong size. I need a SMALL cap to fit what I believe is a Canton radiator tank. Not the screw on type, the old style type with the tangs , you have to press down on and turn to lock in place....but it has to be a SMALL diameter size. Anyone know where I can order one? Thanks in advance for any and all help.