Is this perhaps a question about how high a ratio rockers one could run?
I haven't a clue what (if any) angle is already built into the lifter-to-pushrod "line."
I can say this: I just measured my 1.80 and 1.85 modded stock rockers with digital caliper, from oil-hole in pushrod seat to back edge of rocker:
1.85'*: 0.350 +/- 0.004 inch (1% RSD)
1.80'*: 0.28 +/- 0.01 inch (4% RSD)
I don't know where the original seat was, but even if we moved it back ALL THE WAY, i.e., 0.350 inches (obviously not possible, but bear with me), we have created a triangle with an opposite side of 0.35 inches and an adjacent of about 7 inches (stock pushrod length).
A bit of quick trig:
gives us a change in angle of only 2.86 degrees at the lifter.
(It'* likely that the seat couldn't have been moved more than 0.20" from it'* original position on the 1.85 modded rocker, and this yields an angle of only 1.64 degrees)
As the rocker travels through it'* motion, you'd have to measure a change in this opposite side of something like 0.5 inches to get to a 4-degree angle at the lifter; however, the valve-tip contact patch on the end of the rocker measures less than a quarter-inch, so that defines the limit of our range of motion.
In short, even with 1.85 (or even 1.9) rockers, the rocker end of the pushrod will never go more than 0.45 to 0.5 inches out of line with its original line. That equates to 4 begrees or less of change from the original angle (though, as I say, I do not know what that original angle is). Furthermore, the change from stock rockers to as high as 1.9'* introduces less than 2 degrees change from whatever the original angle was.
I don't know if this helped you, but it helped ease my mind about high ratio rockers!
(I guess the same analysis would hold for cams up to say .520 total lift)
EDIT: I assume you are talking about a 3800 engine