I'll take a look when I get home
I think 1st gear is between 90-95MPH, 6th around 220MPH, can go close to 300mph when doing long runs.
Those are the the numbers next to the gear ratios of each gear.
Like I said not sure about suspension and LSD so you can start by keeping those at default.
Launching has been so inconsistent so I can't tell if a change I did made the car faster or not.