I think you will notice the 1st gear ratio change if you fit the standard T9 box. My MT75 box also has a similar short 1st gear and it is useless unless you're taking a fully laden Ford Sierra towing a caravan up the side of a mountain.
It's why I have been looking at the Mazda box which has a good spread of ratios for Sports car use and still with a good overdrive in 5th.
I now know that the Mazda is not an easy fit in your car so if you are going to fit the T9, I would really suggest you look at the alternative ratio set which whilst being quite expensive will be a much better driving experience.
I'm also not sure about the numbers changing the axle ratio will make if the original is 3.97:1
At 3000rpm the difference will only be about 100 rpm, not 300 rpm. It's only about 3%
The final drive on mine is 3.73 and that would give about a 300 rpm difference at 4.1.
Haven't noticed it at all but then again I only use first gear for moving off.
An alternative would be to get a gear cluster from a V6 Type 9 and modify (shorten the input shaft) which would give you the benefit if an improved 1st gear. The downside of that is that you will end up using parts from two different boxes which is poor engineering practice
Arwyn
