Originally Posted by phunk

For what it’s worth, the stock VQ fasteners spec is 30# + 190 degrees (95 + 95).

That’s 80 degrees more rotation in the VR fastener over the VQ. They are both 1.25mm thread pitch, so that simplifies the pondering a little.

Being the same thread pitch is the only reason we could do it without going even larger then bringing it back down with thread inserts. Drilling up 1mm doesn’t clear out the original threads. But since they are the same pitch, we could carefully start the m12 tap in what was left of the original threads to oversized them just 1mm. It takes great care.

Also, the bolts are MUCH longer.

Then making them fit the heads was a whole other adventure. We made a fixture for mounting the heads into the CNC for machining programs to be run on them.