Rear ends -- Demystify me please

I have a 94SC and i was told i have an 'open' diff. I wanted to know how this type of differential compared to the rear ends in earlier birds. IS Trac-Loc the same as the open diff in my car or would be it worth while to snatch a rear end out of a junkyard tbird and rebuid it ?

"Open Diff" means that with such a differential, all the power goes to the axle with the least resistance. (thus the spinning wheel gets all the power.)

94+ Thunderbird SC's moved to a Traction Control system that uses the ABS system to apply brake force to the wheel that is slipping thus increasing it's resistance which reduces the power an open diff sends to that axle, giving the axle with more traction more power.

This is basically what "Trac-Loc" differentials do, but they do it by mechanical means inside the differential with clutches.

The disadvantage to Traction Control systems (for performance freaks) is that they work by using the brakes to slow your acceleration. Trac-Loc systems attempt to maintain your acceleration. Thus you can spin both wheels with Trac-Loc, but with Traction Control, the computer will be trying to prevent any wheel from spinning.

FYI "Open" Diff. is only found in the Automatics, Stick cars are still Trac-loc's.