10. The sixth head bolt was a real pain to secure. The problem is that the nut is right up against the block making it impossible to get a closed-end wrench onto it. An open-end wrench would make things easy, but that’s a “no-go” with a 12-point nut like what was in the ARP kit. Our solution was to grind down a cheap 3/8-inch wrench as a sacrifice to the engine gods. We sent ARP a note that life would be easier if these were six-point nuts.