96-99 RE's use a different temp/pressure sensor than 2000 up. They read differently and should not be exchanged. The older style has a four prong oval connector and is a round metal sensor. The 2000 and up sensor uses a four prong rectangle connector and is a square plastic sensor.
However, if you have your old valvebody you can swap the old harness along with the sensor and solenoid from your 98 into the 2000 and install in your truck.
If your new transmission is "built" and has a shift kit, see if there is a resistor in the red wire on the new transmission harness between the plug and the sensor. If so, remove and solder into the red wire on the '98 harness when you swap it into the 2000.
As already mentioned, make sure the new trans is a 2000 with the old style NSS and not the 01 and later PRNDL switch! These cases are different and require an adapter to convert to the older switch, along with a valvebody swap.