Well, the OP threw down the gauntlet and I foolishly picked it up.... at least for the 273 adjustable rockers. Set this all up and got better results than I expected, even up to .505" valve lift.
Here are data points using .010" valve lift as a baseline; first number is valve lift & 2nd number is ratio, computed as pushrod lift delta from baseline divided into valve lift delta from baseline. The ratio's listed in this tabulation do NOT include the loss of ratio caused by the pushrod to lifter angle. (More on that below)
0.028/1.64
0.061/1.50
0.100/1.55
0.141/1.56
0.174/1.56
0.204/1.55
0.230/1.53
0.256/1.53
0.283/1.53
0.309/1.54
0.340/1.53
0.383/1.53
0.447/1.56
0.505/1.55
I'd ignore out the 1st 2 numbers (as they are computed from very small deltas and so prone to error); the average of the rest of the numbers is 1.54 (excluding lifter-to-pushrod angle). This includes pushrod-to-rocker angles changes and rocker-to-valve tip changes.
If you want to factor in ratio loss for the the pushrod-to-lifter angle (for a 14 degree angle), that is .970. Multiply that by the average above and you get an overall lifter to valve ratio of 1.49-1.50 for lifts up through .500" or thereabouts.
What is really interesting IMHO is that the ratio stays steady up to high lifts. One would expect that ratio to drop as the rocker angles down more and more. But, the rocker contact point on the valve tip 'walks' further and further out as the lift increases; this outward movement in the rocker-to-valve contact point increases the ratio enough to compensate for the loss of ratio due to the increasing angle of the rocker. Pretty neato! Juuust maybe those Chrysler engineers back-in-the-day could do a lot more on paper than we might give them credit for LOL
You can see the rocker-to-contact point movement in the last 2 pix; the first is at .100" valve lift and the next is at .505" valve lift.
Below is a pix of the setup, which was worked on to make it repeatable and stable. The rockers' adjuster was put where there were about equal threads exposed above and below the rocker body, which seemed like a reasonable place to which to adjust it. The head is a 675 head with the stock. You can see the shims (feeler gages) used to change change the pushrod height; they would be set and measured separately for accuracy.
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