The Stovebolt Site Forums The Parking Lot Panels 'N Burbs Chevy Suburban, differences and desirability

They are both good transmissions for what they were designed to do.

The they both have the same ratio in high gear (1.00:1 - direct drive).

The 4-speed has a very low first gear.
The 4-speed is considered to be a very heavy duty transmission.

Changing the 47-55 1/2 ton rear end ring & pinion to a 3.55 gives you the same higher speed at the same lower RPM.