[jku72]

There is a difference between light and heavy duty coils. I expect the light duty coils would squat more, but the biggest difference to me would be bushings on the rear control arms, the panhard bar, or whatever the centering rod is called, tires and shocks. The front end also has to be good. If any of those components is is worn or not heavy duty, it might well tow like crap. The springs only affect the squat.