The engine mount to firewall is AN6-24 (3/8 - 24 thread). Each complete turn of a nut moves the nut 0.0416 inches divided by 6 castle windows means each 1/6th turn of the nut moves the nut about 0.007 inches. The plans also call for AN 960-616 washer is 0.063 thick "typical" meaning use what you need to get the correct torque at the precise time the castle windows line up so you can install a cotter pin. To get all this done, I also had to install 4 AN960-616L (0.032 thick) which allowed for 175 inch pounds of torque when the castle windows aligned. Spec calls for 160-190 inch pounds.
