The spring rates issue really seems to be a can of worms. You don't hear it too much anymore, but especially in IT there was the east vs west coast set-ups. The east coast guys liked stiff spring rates, stiffer up front, with small bars, and the west coast the exact opposite. Here's a VERY good thread on the topic: http://zdriver.com/forum/showthread.php?t=6075 From what he's written, your numbers seem to be in the ballpark, even with the stiffer up front, but you might still want to try a slightly stiffer rear spring. Basically I have a west coast setup on my car, which I run 225/50/15 Kumhos on. I must have gotten lucky with the setup, because right out of the box it was pretty good, and it doesn't push much. I'm at the 250 front/275 rear numbers which he scoffs at, but it feels real good to me. I'm running a 1.125 front bar and a 7/8 rear. He mentioned chassis distortion, but my car is more like a production class chassis, which much more rigid than an IT car. It seems like the toe setting is critical on these cars. Right now I'm at about 1/32 in on the front, but many guys run a slight toe out, which he describes as well. Also, this will bake your noodle. I remember a discussion on HybridZ a while back about NOT running the same spring rates on all 4 corners. I was talking with a local autocrosser, Mike Tews, who also co-drives John Anderson's Z at the soloII nationals. This car is very competetive. If I remember correctly, he said they were using 300lb on all 4.