steering and handeling help, 73 duster

You really should mark (scribe) the tires. You can easily make a pointer to do that. This creates a "plane" that shows the true rotational plane of the tires.

"Crackedback" just jacks a pair of 2x4's up against the sides of the tires in the approx. middle of the tires and measures between them.

But "following the road" is usually something loose/ worn/ broken and can also be tires that have been previously worn in in a bad way