Quote from: "junkyardjeff"Right now it does better then the original 352 around town so even with the 3.54 gears I will need overdrive on the highway so I will have to decide if I want to keep the C-6 and add a Gear vendor type o/d or go with a manual trans and find a NV4500,
Problem with the C6 is that it does not have a lockup converter, and fitting an overdrive to it may not help as much as you expect.
If you want to stay auto, how about an E40D transmission ?
This has both an overdrive and a lockup converter, and being electronic, you can tune the electronic brain to work exactly how you want it to work.
Or go full manual transmission.
Taller gear may only be of benefit if you live in dead flat country.
If you live in the hills, taller gear than 3.54 may actually hurt economy.
A good spread of ratios + overdrive will give the best of everything.