I mount the eng. to the mnt. and turn the fuse pointing straight up and secure to my work bench. Then i set the motor and mount in the nose so it's just resting on the firewall, now you can slide it around and possition for perfect spinner alignment and make cylinder head in pointing where you want it {normally straight down}, Then I take a little thin ca in a few spots around the mount to hold it in place. when it's secure I carefully remove the engine from the beams and slide it out of the plane. Next either mark the mounting holes or just drill the holes using the mount as a guide, carefully pri the mount off the firewall and install blind nuts or whatever you use. Done!