Yes, I went 3.9 on advice. Mark Shead said the Cossie is massively overgeared and the 3.9 brings it to life, I have 16 inch wheels and now I have close ratio oppliger 4x4 box and with 469bhp and 500ftlb acceleration was vivid to say the least in my little 205 shell, it tops out at 160mph now.