So, I've decided to go with KYB gas adjust shocks on my mustang, but am on a budget so if I don't have to I don't want to replace my springs, but should this be done when my shocks are replaced?

 

These aren't like struts, no need to replace springs unless they're broken
or the car is sagging.

 

Or you want a stiffer ride by going to a spring with a higher rate.

 

Also, you don't have to remove the springs to remove the shocks. It's much easier to replace the shocks than the springs.

 

though not reuired, if they are the original springs, I would replace them. for about 80 bucks you can get 560 rated springs from opentracker.

Does your car bottom out at all on big dips the road? If so, they should be replaced. They will make a big difference in the handling of your car too.