Send the H&R springs back. You'll going to end up with way to much power for just H&R springs. Bilstein PSS10 coil overs at a minimum if you don't intend to track it. Beyond that start looking at some of the more serious coil over systems posted on the board (Motons etc). H&R or GT2 rear sway bar with drop links also a minimum requirement to control all the understeer. If you're running stock 18" wheels and tires this should be fine unless you plan to lower it to GT2 ride height or if you plan to go to 19's with wider rubber you'll need rear dog bones and toe steer links to acheive proper camber and toe on the street. Also consider Wevo motor mounts and the ungraded 997TT tranny mount. A 997SS shift linkage is also suggested. Do it all at once and do it right. In the long run you'll save lots of money and frustration.

 

I had a straight pipe procharged 427 z06 as a dd so I doubt I'll have a problem with it. All good suggestions I'll look into it all