I havnt run the car down the track yet at 560hp. I launched the car @ 17psi and snapped the stock diff, heres a pic. I have put in a kaaz with solid mounts and chromolly axles since then.

 

I have a GT42R in my FC. I bought it on Ebay new for $1500. Before, I had a Turbonetics 62-1 and the difference is huge. It used to make around 410rwhp at 19psi and now it makes 485 at the same boost. I was able to get 537rwhp at 24 psi, but broke the transmission on the dyno before I could fine tune it.