does anyone know anything about NP 4speed overdrive transmissions used in mid/late 80's - early 90's GM pickups ?
if so, were these the same transmissions used in dodge pickups ?
similar but different case to bellhousing bolt patterns ?
same or different output shaft spline count ?

my one buddy was talking about a transmission another guy had, and said it was a new process 4spd overdrive out of a chevy pickup.
anyone have anything on this animal ?
as always, TIA !