Third Member Rear End

How exactly does a third member rear end work? Does anybody know of a good website explaining the physics/dynamics of it?? Curious Z28 owner/ engineering student.

Hmmm....well, lewd jokes aside...
This refers to an axle where the pinion shaft, pinion gear and spider gears (the differential gear assembly) is mounted in a seperate cast steel carrier (like a frame) This carrier is inserted into a cavity in the axle housing and bolted together.
The Ford '9 inch' rear axle, made from 1958 to 1979 (or later) is the most common auto axle of this type, although every meduim and heavy duty truck uses this format as well.
The advantage of this type (over the type found in your Camaro) is ease of serviceability. The differential gears can be removed in one easy to service module.

i heard somewhere that the third member rear-end harnessed the torque of the motor and used it to "press" the tires to the gound.

The open differential is an inginious invention it is acually quite simple once you understand how it works. The 2 wheels on the axles average speed is the carrier speed. This allows you to go around a corner whiile mantaining the same road speed but alowing the tires to move at different speeds from each other so they do not scub. A good web sight for explaining it is called "how things work" check it out

i heard somewhere that the third member rear-end harnessed the torque of the motor and used it to "press" the tires to the gound.
That is a function of suspension geometry, mostly. The actual axle design is largely irrelevant.