While we’re on the subject, why do the ring gear bolts (factory and aftermarket) only thread in 1/4” when they still have 1/4” left to go? The extra depth would add much more strength.
Doesn't add strength. If the fastener bottoms out in the hole before the clamp load is achieved, the parts are not actually held together.
Bolt torque isn't what is actually the desired result of tightening a fastener, it is bolt stretch. Torque is just an easy way to get a close stretch measurement. As variables change, so does the required torque to reach a desired bolt stretch. How clean are the threads? Lube on them (loctite will act as a lube until it sets up). The type of lube as well (ARP specs different torques for different lubes). Material it is made of (ARP often publishes different bolt torque numbers than OE specs). Even the finish of the threads. ARP sells a bolt stretch gauge for tightening rod bolts. You use a box end wrench and tighten until you hit your stretch number. I have even heard of using ultrasonic gauges to measure the length of a bolt when you can't access the back side to do a measurement.
There is more to getting the correctly tightened fastener than a few more threads for it to screw into.
