I would go with the 3.70.
Here's what the different ratios will yield in 6th gear with that trans.
3.70 3.89 4.10
8000 RPM 259.75 MPH 247.06 MPH 234.41 MPH
7500 RPM 243.51 MPH 231.62 MPH 219.76 MPH
7000 RPM 227.28 MPH 216.18 MPH 205.11 MPH
6500 RPM 211.05 MPH 200.74 MPH 190.46 MPH
6000 RPM 194.81 MPH 185.30 MPH 175.80 MPH
5500 RPM 178.58 MPH 169.85 MPH 161.15 MPH
5000 RPM 162.34 MPH 154.41 MPH 146.50 MPH
4500 RPM 146.11 MPH 138.97 MPH 131.85 MPH
4000 RPM 129.87 MPH 123.53 MPH 117.20 MPH
3500 RPM 113.64 MPH 108.09 MPH 102.55 MPH
3000 RPM 97.41 MPH 92.65 MPH 87.90 MPH
2500 RPM 81.17 MPH 77.21 MPH 73.25 MPH
2000 RPM 64.94 MPH 61.77 MPH 58.60 MPH
1500 RPM 48.70 MPH 46.32 MPH 43.95 MPH
1000 RPM 32.47 MPH 30.88 MPH 29.30 MPH
You can go to the Wallace Calculator and play with ratios
http://www.wallaceracing.com/gear-speed.php