Thanks for the quick reply. What kind of adapter? I have opportunity to purchase a SS grip frame, but don't want spend a whole lot on the gunsmithing. Thanks again!
If the new grip frame is a locking frame, you will need the lock and shorter strut and spring that comes with it. Or, you can modify the lock grip frame to accept the longer spring and strut from the non-locking grip frames. I am sure it is pretty simple, but I have never personally modified one.
He said an "older New Model". He will not need an adaptor to put the XR3 Flat Top Blackhawk grip frame on any New Model. He will need to use the internal lock. Or make this longer spring perch in place of the lock: