This adapter kit will adapt the New GM automatic 6L90E 4WD to the GM NP205 transfer case with circular 6 front bolt pattern. Kit 50-9552A, 6L90E adapter assembly includes new female 29 spline NP205 input gear and shaft, NP205 adapter ring, 6L90E conversion tail housing, input shaft bearing and fastening hardware.
This adapter assembly fits the GM NP205 part time transfer case. The GM version is a part time, cast iron and offers a 32 spline female input gear, circular six front bolt pattern and a passenger side front out put shaft. Used from 1985-1991 GM 1 ton trucks
GM's new Hydra-Matic 6L90 transmissions are the first of a new family of modular six-speed rear-drive transmissions. The transmissions feature two overdrive gears and a wide, 6.04:1 gear ratio spread to improve performance and fuel economy when compared with conventional four- and five-speed automatic transmissions. With two overdrive gears, engine rpm is reduced by approximately 9 percent at 60 mph - a reduction to about 1,500 rpm. Lower engine rpm can bolster fuel economy because less fuel is used. A lower-rpm cruising speed also enhances smoothness and reduces noise heard in the vehicle's cabin.