Rick and Steve:
Even with my modified 2V heads the car is able to run (real) 265 Km/h (164.7 mph) on the Autobahn at 5800 rpm with a 2.88 rear end and a Tremec 3550 in 4th gear...
You can wind up higher untill 6800 if you want but you don't want to do so in 4th gear, beleave me.
After 2 or 3 Kilometers distance with a Porsche in front of you(before acceleration at 150 Km/h) and afterwards behind you(265 Km/h), you will lift your right feed by yourself, slow a bit down and wave him to pass you again with a grin in your face
But you will need 5 minutes to dry again, and your back is still soaked with sweat the next 20 minutes.
Our cars getting very, very, very light at the front above 240 Km/h.....
Uwe