1979 5.0 Heavy Duty Suspension??? Help

I'm try'ng to order new front end suspension bushings. Some are listed for "heavy duty" suspension, how can I tell if the front suspension is heavy duty or not?

This is a 1979 5.0l automatic Ghia (coupe if it matters) package. This is an issue primarily with the lower control arm bushings. How can I tell if it's "heavy duty" or not?
 
This is something you have to decide for yourself.
If you want the car to respond quicker in corners, or if you're not happy about how the car handles in the front when braking very hard, you could try to upgrade the bushings to 'heavy duty'.
I like a smooth ride so I choose stock or something in between.

If you're wondering what you currently have installed, try to check if they are rubber or hard 'plastic' (polyutherane).
If they're worn out the rubber could've become hard, so it's not always easy to tell.

Hope this helps,

Phil
 
The rubber ones are the standard ones. They give a soft ride.

The heavy duty ones are polyurethane they are more for performance/handling.

All the bushings for the arms are the same size whether they are heavy duty or not. Just a matter of preference.