Minor fitting may be needed to get the frame/grip frame flush, but yes the birds had frames will fit. Ruger actually cataloged a long (7 1/2") Vaquero with a birds head frame for one year. I believe it was in .44 magnum but I never have actually seen one. They also made small runs of Vaqueros in 45, and 357 with the birds head grip frame also, some cataloged, others weren't.