Might be worth doing some extended research on it, with the torque and rev range your motor has perhaps a slight change of ratios or different final ratio could be an interesting option, might be worth speaking to some of the guys on the Fiat coupe forum basically quite a few on there running a gearbox of the same family putting through 470+bhp and 400+ lbs of torque, perhaps talk to these guys
www.torqueitalia.com