Don Terrill’s Speed-Talk

You are right. The tensile strength of a AN bolt is about the same as a grade 5 bolt. However the biggest factor is that normal grade 5 and 8 bolts are designed for more of a tensile loading setup while an AN bolt is designed more for shear and is more flexible and has a much better fatigue factor.

As a last resort, you could have a machine shop make you a few from aircraft Hy-Tuff AMS 6425.
It is readily available and has tensile around 230K.