When did your rad swap did you burp the system? Had the same problem when i did my rad/water pump and couldn't figure it out. Finally burped my system and then my head gaskets blew out. Due to running it without burping the system. If you hadn't burped it then burp it and definitely trace those puddles to where they are coming from. You might have a slightly cracked hose somewhere. This includes your heater hoses.