The VGTT motor in the Z has out run the JZ motor in a Supra in both 1/4 mile and top speed. When money is no object you can see that Z's in Pro racing are running low, low 7 seconds and Supra's are not even in 7 seconds.
Top speed record is the 300zx and that's cars built by JUN, please see there web site. The Z set the record one year in production ( 1991 ) of 260MPH and the Supra did it's run some ten years later ( 2001 ) and did 240MPH. This is when money is no object and you come looking to break records, while using your base motor.