Steering Column Help

Maybe you can shed some light on this since it has been suggested before...
Given the difference of approx 3 inches between power and manual, Do you know how much overlap the 2 pieces will have after extending a p/s shaft the 3 inches?
What is adequate or minimal connection ?
I think I'd rather have a manual shaft that had been collapsed for power steering instead. Either way means screwing around with one of the very few safety features these cars have.