From 8 to 9 to 1, the gain is more then going from 9 to 10, same with going from 10 to 11
The later year cars got 3.23 gears vs 3.55 - 3.91 even 4.10 gears, that alone makes a big difference..you could get 3.55 gears from the factory in 1973 but not many cars did..as SS used to say, 3.55's are **** gears, same performance as 3.23 and same MPG as 3.91's
The 340 really needs 4.10 - 4.30 gears to run strong IMO, its built to rev, let it and it will surprise you
