open editor> far right upper icon "speedo">speedometer tab (upper left)>lower left final drive ratio>ratio

I havent done any tuning since I was racing my 3800's years ago so I am rusty but I believe on these rwd cars its as simple as changing that rear ratio number someone please chime in whos done a gear swap in one of these if I am correct( fwd's are more complicated because you enter a number different that your gear ratio because drive chain and diffs both can vary in ratio)

 

Thanks I went out there and I found it. I seen where it has a spot for my gear and tire size now and I gotta put in my new gear ratio and tire size then I guess I hit commit..