I feel your pain! Changing the ride height really screws up the process. Traditionally the trans output is higher than the pinion input so achieving the appropriate angles is fairly simple and direct. Its when you lower these early mustangs and the pinion height is now equal or higher than the trans output which limits your available movement. You don't want to turn your pinion angle up because too much torque will put the pinion nose up into the floor pan and worse case you slide the DS out of the trans tail under hard launch.