[Brian]

I can't really answer your question, however I have owned my car since 1971, done a bunch of miles...I've tried all sorts of gear combinations, I find 3.78 is the best 'all round' ratio; you'll get off the line respectably, and have a good top end. A 3.54 rear is good at highway speeds, but the acceleration will suffer, takes a bit of the fun out of it!