I want to set up my 71 Charger to be flat-towed by my 93 Ram Van

[YY1]

...and you can use the trailer to help move.

Sofa, bed, fridge, etc on one trip, car on the next.

 

[jenkins71]

You better also consider the rear axle before ground towing. Sure - Grips should not be towed long distances on the ground and speeds are recommended at 45 mph.

How is the rear end "know" it's being towed rather than being driven? Either way the gear is still spinning in oil....

 

[mopar 3 B]

How is the rear end "know" it's being towed rather than being driven? Either way the gear is still spinning in oil....

Consult the FSM or an owner's manual. Also consider the way the suregrip is being loaded. Is was designed to be driven from the pinion, not the rear tires.