I used the 3:31 ratio in my '89s that I've had as a matter of fact I have a set in my garage that I didn't get to install in my last '89 GT. I also have 3 1/2" straight stainless tips that I never installed on the '89 LX. I should probably list them for sale lol
I've thought about selling the 3.73 ring & pinion but new they're only around $160 or so. I wouldn't make enough on my used set to make them worth selling.