Good question !

The 632 Shivvy specs out :

Camshaft Type: Billet Steel Hydraulic Roller
Valve Lift (in.): 0.780 intake/0.782 exhaust
Camshaft Duration (@0.050 in.): 270º intake/287º exhaust, 113 LSA
Cylinder Heads: Aluminum spread-port; 70cc chambers -RS-X design
Valve Size (in.): 2.450 intake/1.800 exhaust,Titanium (5/16-in stem OD)

So it has lighter, small stem Ti valves, shaft rockers, and a steep 1.8 rocker ratio. The actual lobe lift would be a lot less, who knows what spring they're using to control it. I believe the lifters have a .904 or slightly larger” diameter body with a .850” wheel on needle bearings. At 12:1 cr, you'd think it has smallish chambers, flat tops and a supertight quench. Note the LSA.

Hemi is a different engine/different design so has different challenges for hyd cams that rpm. I believe pushrod angles in the hemi design load up the juice lifters and have clearance issues in the head/block if its a decent lift cam. Long exh rockers add valvetrain mass as well.

Whos using a decent lift juice roller in a big inch Hemi? Not saying it can't be done, but from what I've read, it seems to be more trouble that its worth given the limited choices we have with this platform compared to the General Maintenance crowd.