I totally agree with nm9stheham !
I too did some R&D several years ago and found very similar ratio's. I got 1.53:1
Keep in mind, the geometry of the LA heads is not perfect, that's the reason the ratio changes slightly through the lift cycle.
Without spending a bunch of money, I have always used .050 taller stem height, and ran the adjuster as close to the rocker as possible. (longer/custom length pushrods)
FYI these rockers can also be re-ratio'd with larger adjusters to go well beyond 1.6:1 (did several set's in the past) (with no breakage !!!)