3.09 4 Speed Gear Set Strength

It’s still an 833. It’s as strong as any other.
That ain't quite true. Some gearsets are stronger than others, same in a rear axle. Generally, lower gear ring / pinions are weaker than higher geared ring/ pinions. "I've always been told" the 3:1 low is weaker. It makes sense because the driver gear on the cluster is smaller