Will a 1995 Gmc 2500 van transmission 700r with overdrive fit in 1990 it also had 700 r out overdrive?

While both vans used the 700R4 (later renamed 4L60E) transmission with overdrive, a direct swap isn't guaranteed. There are subtle differences between 700R4/4L60E transmissions across model years and even within the same year depending on engine and options.

Possible Issues:

* Length: While the overall design is similar, there might be slight differences in length. This could affect the driveshaft length and possibly the transmission's fit within the bellhousing.

* Electrical Connections: The wiring harness connectors for the transmission controls may be slightly different. You might need to modify the wiring harness or use an adapter.

* Valve Body: Internal valve body calibrations can vary between years, possibly affecting shift points and performance. While not a deal breaker, it could lead to suboptimal shifting.

* Torque Converter: The torque converter is integral to the transmission and should ideally match the engine and transmission year.

In short: It *might* fit, but it's not a sure thing. A professional transmission shop or experienced mechanic should inspect both transmissions to determine compatibility before attempting the swap. Simply because they both say "700R4/4L60E" doesn't guarantee interchangeability. The specific application details are crucial.