32psi on a GT4276. 4-link backhalf, ford 9", 31x10.5w tires. Cilp 8.59 @ 158 mph http://www.youtube.com/watch?v=T4EKyOt4rNI Cilp 8.92 @ 147 mph http://www.youtube.com/watch?v=bXkuHZkyk-c Cilp 8.63 @ 158 mph http://www.youtube.com/watch?v=n6D6-DLqB_Y&mode=related&search= Cilp 8.72 @ 155 mph http://www.youtube.com/watch?v=FeLXQdxiLDM&mode=related&search= . . .