I put a set of Richmond gears and an Eaton posi-trac in a 70 Z28 Camaro ans race cars and had no problems. Also I raced dirt oval with as spool and Richmond gears with them no problem. I wished I had broke them, but broke excel instead. The track finaly got smart and let us run 9” Ford rears. I had already built the last dirt rear end before they change the rules to be able to use a 9” Ford. Just rebuild everything, clean with varsol (paint thinner, inside and out) then change bearings, seals, everything (the rebuild kit is worth it). The main issue in rebuilding it is getting the pinion slack right, not too much and not a little of slack both will cause a winding noise. Some people on here may not have had the pleasure shimming starters through this, but back in the day you had to shim starters on your motors. You had to bolt it up, put silly putty the ring gear of the flex plate, in-gauge the bendix w/ a screw driver, rotate the motor from the crank and check it, then do it again till you shimmed it to the right slack for proper clearance. With the pinion install DO NO tighten the nut all the way with out checking in the slack, just have your car in natural, on jacks stands and rotate your driveshaft back in forth to check it using the method above or I can listen to it from experience. It’s a good idea to have a few crush sleeves on hand, only one comes in the rebuild kit. I have not done a rear-end on a Mustang, but when I do I will probably go with Ford Racing or Motive gears.if money is not an issue here is a link of my tuner, and these gears are suppose the be the latest trick of the week. I just took my medication and am rambling, I hope this helps, good luck if you have any question please ask.
1996 GT (sold)
1993 Ranger GT (not broke)
Want an 03/04 Cobra
Born:5/23/97, Build # 5722 of 6961 Builds