By sport set do you mean Cen's threaded shocks? The threaded shocks come with 2 sets of springs, hard and soft(or at least mine did). Check which ones you are using.
The rear springs don't need to push the car up to the very top either, a little slack in the rear at res is fine just take it for a spin and see how it handles and if it bottoms out.
If you really want eh back higher you can use stiffer springs or use the spacers that come with the shocks. Just slide the spring down and clip on one of the spacers around the shock body. The spacers look like this if you dont know what i mean. -C