Don,

I don't understand the 1600 rpm lockup you mentioned. How is that accomplished? Just based on converter stall?

The reason I went with Bowtie Overdrives was the positive electronic lockup in 4th gear. As long as the car has shifted up to overdrive, the converter is locked, and the manual switch allows the same in 2nd and 3rd. As I understand it, if the RPM drops below the stall of the converter, the transmission still stays locked. It will downshift and unlock if I hit the loud pedal, or if I move the shifter lever, but otherwise, stays in high gear and locked.