I took it for a drive Sunday before I took the driveshaft in.
The 3:55 gears raised my RPM's at 80mph from 2,100 to about 2,500.
I was expecting about an 800 RPM increase using OD with lockup, but I'm totally fine with the outcome.
It sure is a lot more snappy around town though, and the gear reduction coupled with the Sure Grip and stickier tires made a big difference.
If you are spinning tires out of a corner you really need to have the car pointed in the direction you want to go when the tires take hold again.:D
Starting to think I may want to get a rev limiter on this thing.