When you say it won't turn the tire, do you mean it actually doesn't want to seem to turn the back tires at all? Or, do you mean that it won't break them lose in a brake stand and lay two big black strips of rubber on the pavement along with a whole bunch of smoke behind you and send the car sideways as it pushes you out of shape?

IF the first question asked above is more correct, I would say that since you are the one that is there with the motor, and seemed to be convinced it's not doing it's job, then run a compression test and see what you get. If the motor is just plain old and tired, that'll tell ya. I really think that your problem lies in the area of the tranny/rear end though. Either the torque convertor is shot and not multiplying the torqure delivered by the engine, the tranny is slipping real bad or something in your rear end/axle area isn't right. Are your rear wheel bearings binding/siezed? Or perhaps your brake shoes sticking?

IF the second question in the first paragraph above is closer to what you're saying, then I would say, change the rear gear ratio. Dave's right (as usual) 2.73's will make any motor seem like a "pooch".

Cheers,
Dutch