I’ve never checked any hemi rockers myself, but I’ve heard from a few people who have that they can actually be as bad as the 1.3x’s.
You’re not too far off from that....... .525 at the valve with a .370 lobe is an effective RR of 1.41.

Hemi rockers that are actually 1.57in/1.52ex as taken from a production engine as delivered from Ma Mopar are probably even rarer than 906 heads that came from the factory with anything even close to 79.5cc chambers.