I use my 1999 Chevy Blazer LT in my work which requires me to keep equiptment in the cargo area. What is the best way to beef up my rear leaf springs so that the rear does not sag?

If the extra weight is always there you can have your springs re-arched and have an extra leaf or two added. If the weight is only there occasionally then overload springs are the way to go. They are added to the existing springs and only come into use as weight is added.

Cheapest sollution would be to install a set of add-a-leafs. Another option would be to install some air shocks in the rear and adjust them according to the load your carrying.

Installing new shocks helped a lot. My installer said the replaced shocks where the originals. My Blazer has 114k miles.