Accuride makes them for snapon. I just got slides through snapon accuride name is on the package but not any cheaper. I have some left over I would sell if your still in need.
Snap on is too pricey I think. Their detents are a little beefier than Kennedys $4.70 for a pair. Here’s the pics of standard and firm detents. My box came with the standard dents on krl 661-691