Jim: I'm not sure of the designation spec for the grip frame. What I can say though is Badger says these grips are for "Blackhawk, Single Six, Old model Vaquero, New Model Super Blackhawk w/ Round Trigger Guard (except Hunter model), Will not fit New Vaquero or 50th Anniversary"
And yep, the backstrap is exposed. The grips extend down past the grip frame about 1/2".
Basically I just called up Badger and said, "Send me something to fit this gun for my gigantic hands", and this is what I got. I actually wanted rosewood, but these were already made so I took 'em.
betes: They certainly are for me. I can't really speak for anyone else, but I find the stock grips to be extremely small and uncomfortable in my hands. To be fair though, gunfighter grips are meant to be held and feel a certain way.. one which I've found I'm not fond of. (This is my only single action gun, I'm a Smith wheelgun guy) Of course this is a .44mag gun though, and the stock grips were hell on my palm.