The lower gearing of the T5 in 1st and 2nd just might work. I ran it with the T56 gearing on my 03 and we would be dropping below 4500.
Side note - I don't understand the infatuation with a T56 in a Cobra roadster. That thing is a big, heavy, mean, SOB. Works well if you drive it hard enough.
Chas your comments and warnings are noted. I can see where one could really screw up.
Off to breakfast
chr