It is sure possible!!! I have done several.
Ya can find all the info in some previous posts on this here forum. Just do a search. I'll wager it will come up in seconds.
All of the movin' parts have the same geometry & screw locations.
You will want hammer, trigger, grip frame, panels, grip roll pin. I am in the market for any extra of the Bisley parts you will remove.
What lock are you talkin' about?
You don't mean a NM Blackhawk of 2004 or newer vintage, are ya?
I am givin' you info on the Blackhawk (large) of 1972 to present day vintage.
PM me if ya need. But the Pards who frequent here are more expert on SA Rugers than I am!!
MG