[Aubrey N Bruneau]

A few reasons, Rory...
I 'm looking at making quite a change, possibly as much as 3.17. The engine has an unusually broad torque curve, so a wide spread between gears, would work fine. This would mean changing at least 3 gear sets.
Another reason, is that I'm paranoid ! This transmission works flawlessly as is. I'd be worried about "disturbing" it, and having something that maybe doesn't work perfectlly.

My own mistake. I simply ordered the wrong gear ratios for my car.
For a light car.... it's perfect.

BTW, I should mention... This particular transmission uses GM 26 spline input, with the large GM M22 / TH 400 size output. The case and configuration replaces a regular GM Muncie M22 or B/W Super T10.