I have 3.08 gears in the rear of my '55 1st Suburban. Running a GMC 270 and a sm420.
It doesn't like to pull a loaded trailer uphill, but running around without a load the limitations are front suspension, not gearing.
I've been very happy with it.
In the 70's I had a Blazer with 3.08 gears, a 350 and a 4-speed. It did fine (of course it also had a low range).
