Top speed at VIR is limited by testicular size. 4th is good to about 140. If I short shift into 5th 150 comes and goes, I'm too busy finding my nuts, braking, down shifting, watching jt1 go by me in the braking zone, and remembering to turn left to check the speedo.
Tranny is t56, diff is q45, rear tires 245-40-17's