Put the clamp on the hanger in place and snug with the main bolt and then Squeez it down on the hanger by putting a C-clamp on it and then tighten the main bolt.
This way you won’t strip the main bolt.
Ya they do need a lot of force to tighten them. I slightly stripped both the stock bolts. Then I ordered new hardened 12.9 bolts and never looked back. I like the c-clamp idea. Good thinking.
Still looking for this older-style Torque Boards (DIY) mount, if anyone has it. Mount + Clamp.
Come on, sure they sold heaps of those, some of you must have extra! Cheers!