This spacer adapter is 2.125" in length and is used when retro fitting a GM 4L80E 4WD to the 1985-91 GM NP205 with a long input gear. This input gear measures 3.50".This kit does not offer a shifter bracket for the NP205 shifter. You will need to fabricate a linkage bracket. This kit requires a 4wd 4L80E with the factory 4wd tail housing
Transmission: The 4L80E transmission is normally equipped with an internal reluctor ring on both the transmissions input shaft and output shaft. The computer needs both of these readings for the proper shifting and operation of this transmission. The rear reluctor ring is not always installed into the transmission. The basic rule of thumb is 4WD transmissions up to 1996 should have a rear reluctor ring in the main transmission case. All 2WD transmissions should have the rear reluctor in the main transmission case. The 1997 & newer 4WD 4L80E transmissions had a sensor provision; however, the reluctor ring in the transmission was left out. Since it is expensive to disassemble the transmission to add a reluctor ring, this kit has a vehicle speed sensor built in that can be used in place of the 4L80E Output Shaft Speed Sensor.