What is the ring gear diameter? If it is too small, then a higher numerical gear ratio becomes ever closer to a needle-and-pinion gear set, with too few teeth engaging the interface between ring and pinion.
Just an update, finally heard back from the shop that works on my car. The drivers side axle shaft snapped clean just inside of the differential. The piece of the shaft is lodged inside the diff. The passenger side did not snap but is twisted. The shop is sending me pics and I will post when I get them.
The differential is being replaced with a 3.90 unit and the axle shafts are being replaced with G-Force 1500hp rated shafts. I’m also having a Barton installed while it’s there.... because why not lol