[RICK LAKE]

Merv and Sharon I am not sure about what you are going to use the car for but, A couple questions and answer might give you another way to go. You didn't say how much power the motor has and since you are looking a T5 I am guessing in the 375-400 hp range. Is there any way you can find out what the ratios are in the trans? There is nothing bad about using a 4.10 rearend if you match it with a over drive trans in the .80-.78 range with 15" wheels. You would also look for a trans with a 2.20- 2.50 first gear. This would be for the street. Maybe a 2.70 max. My 5spd has a 3.15 first gear and 3.31 ratio in the rearend. I never use first any more.
The other thing is going with a TKO 500 or 600 trans. They are cheaper than a T-56 trans which with the right ratio might be the best choice. The double over drive one. Either one of these trannys have multiple shifter locations which will make driving more comfortable on the road. If you abuse the car a little, over engineer the drivetrain if possible. This will save you money in the long run.
How much will it cost to have the gears swapping in the rearend? Compare that to a stronger trans for the car with an overdrive. Alot of the mustang guys have gone from 3.55 gears to 4.10 for better all around performance. Rick L.