I also have the Hyd roller lifters as well in exc shape. It will need the stack up pieces for the nose of the cam to set the end play. No mods needed to the front cover as the end play is set up with shims in the stack up parts. You can get them from Dan at DLS or I believe Billy Anderson sells them as well.
What kind of application was this orginally for? I have an 8:1 4.1 I'm building with 1.65 T&D's, would this cam be too much for a semi-daily driven street car that sees about 12 passes a year max?
I ran it in my 3.8. It idled at 850-900 rpm at 16" vacuum. Drove excellent on the street. The idle wasnt rough at all. Being that you have a 4.1 I dont think it would be too much at all.