if you use a one piece input shaft you will lose the lockup feature of the tq convertor. on a basically stock or fairly mild 351w a one piece input shaft really isn't needed. i would get a trans with extra clutches, the larger aode od band, the better servo from the t-bird super coupe or an aftermarket servo and a good shift kit or the lentech valve body (lentech VB would be my choice). the shift pattern is still the same as the as any 3 speed ford tranny so need to change anything there, what you have heard about is that the aod does not have a seperate detent for 2nd gear and the trans shifts automatically on it's own from first to second with no real control available to the driver. the lentech valve body kit will redirect the fluid flow so that you will have manual control of all 4 gears with od being an electric push button. so basically you have manual control of 1st, 2nd and third with the shifter, but like i said the detents are the same as a c4, c6, fmx, etc. so you can use the stock shifter from your car.