Oh boy. Valvetrain geometry issues.
I have read different process for measuring pushrod length.
First is to lengthened the checking rod so that it spins wit a little resistance using 1 finger to spin it and lock it, measure an add desired preload.
The second is to lengthen until you can no longer spin it using 2 fingers, then tighten, measure and add desired preload.I
I'm pretty sure the first is correct.