Hello everyone I’ve been a long time reader here but this is my first post. I’m having a very hard time installing a 3.73 gear set in my 86 mustang. I’ve been working on this for several evenings now after work and am getting no where. I’ve done machine work for about 30 years and believe I have a good grasp on how this is supposed to go, but it’s not going that way. No matter weather I have no shim or so much shim under the pinion that the pinion nose hits the carrier my contact patch is on the heel on the drive side and on the toe on the coast side. I have tried shimming the pinion in small steps and setting backlash each time, even varying backlash from .006”to .012”. Nothing moves the drive side contact patch off of the heel of the tooth. It’s a Ford Performance gear set by the way. I’ve also read up some on the face hobbed gears that there using in these rear ends.