show breed pigeon

Hi, I'm looking for more information on American giant Rumblers, I've been having a very hard time finding anything! Are they good parents or do they need pumpers? Do they fly well, or are they like giant runts? How is their fertility? Any show breeders in America, I haven't had any luck...

This is my pigeon that I have rescued from a dog kennel years ago. If nobody wanted her and her mate, which was a modena, they where going to be used for target practice for there dogs, I just could'nt let a beautiful bird get killed, so I took her to my farm and put her in with the rest of my...