The Advance Adapters 23-spline adapter kit (SKU 50-9905) is the counterpart to the 43-spline 6.2L kit, built for swaps using the standard 5.7L HEMI's ZF 8HP70 automatic transmission — the version found in the Ram 1500, Grand Cherokee 5.7L, and Trail Hawk. Unlike the high-output 6.2L transmissions, the 8HP70 behind a 5.7L uses a 23-spline output shaft, so this kit is a straight female-to-male spline match rather than a step-down conversion.
The kit centers on the same 5.7/6.2 8HP70/8HP95 adapter housing (51-9905) used across the Advance Adapters transmission adapter line, paired here with a shaft specced Jeep 23 female x Jeep 23 male (52-9901). That shaft carries the transmission's output straight through to a 23-spline male end, ready to mate with a compatible transfer case input.
One important fitment note straight from the listing: some applications may require the spud shaft to be shortened. That's worth confirming against your specific transfer case and driveline setup before final assembly — it's a heads-up worth passing along rather than assuming a drop-in fit every time.
What's included:
- 5.7 and 6.2 8HP70/8HP95 Adapter Housing (51-9905)
- Shaft, Jeep 23 Female x Jeep 23 Male (52-9901)
- Sealed Bearing 209RS (716308)
- Snap Ring, T350/T400 (716450)
- True Arc Snap Ring (716456)
As with the 43-spline version, the sealed bearing and snap rings come included so the shaft is fully supported and retained in the housing without sourcing those separately.
This is the right pick if you're mating a 5.7L HEMI-based 8HP70 (not the high-output 8HP95) to a transfer case that needs a 23-spline input — a common combination for Ram 1500 and Grand Cherokee-based swaps.