You can ask Comp cams tech about the `Johnson lifters.
I believe its either Johnson or Stanadyne that make the GM HD lifters with the hard alloy face. Comp probabily sells them too.
You just have to ask.
Thats what the tech line is for.
I`ve found them very help full.
I used the common speed pro HT-817 hyd lifters on this cam.
I don`t have big problems with cams.
I like this stuff