I guess I haven't seen many Zetec dyno graphs, so you'd have to take into consideration where your power drops off. Seems like if your powerband was more towards midrange, the 4.06 would be the way to go. If you are still making power to redline, then you may keep the zetec FD.
I think this is a big reason why most of the Camaro/TransAm/Vette guys go to a 4:10 gearing.
Where's Greg with his more technical approach?
Mark
