A PD blower gives you the instant TQ hit. The story I got was the force on the rods goes up to the square of the rpm. Then I also heard the force on the rods goes up to the cube of the rpm. If you do the maths, > 6500 rpm is pushing your luck. Window the block, and your day is done.
Plenty of FRPP setups with the 11 psi boost setups that have windowed the block. Their lower 9 psi setups fared a bit better. Those are both PD blowers. Even the cops had a modified mustang for hwy use, with the 11 psi FRPP setup, and they windowed the block. It did not last very long either.
Typ, on a centrifugal, the boost goes up to the square of the rpm, so I can see wanting to shift higher.
On my 2010 GT, it's a 5r55s automatic, and 2nd gear in the 5r55s is 14% lower than 2nd gear in the TR3650. 3rd gear in the 5r55s is 16.5% lower than 3rd gear in the TR3650. Where I lose it, is when shifting from 3-4 at 6 krpm, then it drops to just 3500 rpm.