When I chose the parts for my car, I picked a T56 and planned to use the last two gears for freeway driving.
I used a toploader for three years and it worked well, my mileage was like 4 to 6 miles per gallon. With the 5 speed and the large drop in RPMs to do 70 on the freeway, I have seen my mileage jump to 20 and more miles per gallon.
For me, it was just adding the TKO600.
