[Formulas]

When I did my #47s I used a aviation structure tool called a Steamboat. Snatch block, Bushing block, bolt it down to the head or use a big C'clamp what it does is keep whatever your doing drilling or tapping at a 90° angle to the work surface

That said ball socket pushrod and ball socket rocker fulcrum should allow you some variation in your results without catastrophic results, full roller rockers will transfer the misalignment to the rocker body more depending on which way the stud is off.

I would re,adjust and make sure poly,locks are tight before throwing in the towel or try cinch nuts