Is There A Sidewinder Pin Box That Replaces The Leland AF 7921 Pin Box?

Updated 01/02/2026 | Published 10/07/2024

Products Featured in This Question

Trailair Air Ride 5th Wheel King Pin - Leland 7920 - 21,000 lbs

(83)

$1625.07

MORryde Cushioned 5th Wheel Pin Box for 14K to 18K Trailers w/ Dexter 221002300 or Leland 7920/7921

(249)

$942.52

Question:

Looking to get a sidewinder due to having a 2019 Ram 3500 Megacab 61/2 ft bed with Ram boxes. Have a 2006 KZ Durango 5th wheel with a Leland AF 7921 pin box. Found that I need the ST400 turret to fit this pin box but am having a hard time finding that adapter.

asked by: Brandon T

Leland AF 7921 pin box
(click to enlarge)

Expert Reply:

Hello Brandon, thanks for reaching out. Sadly, there is no sidewinder that will replace the Leland AF 7921 pin box. The only pin boxes we carry that replace it are cushioned pin boxes like the Trailair Air Ride 5th Wheel King Pin # UF35-946208 or the MORryde Cushioned 5th Wheel Pin Box # MR52VR. With there being no sidewinder options, there really is not a good way to pull your 5th wheel with a tuck with Ramboxes. The only thing to do would be to get a different 5th wheel, or to convert your Rambox bed to the standard bed.

The ST400 turret you mentioned is unfortunately discontinued. We sold our last one about 2 years ago and we will not be getting more stock. So unless you can find one secondhand you will have to go in a different direction here.

expert reply by: Jesse M

Jesse M.

12/22/2025

Hey Brandon, what direction did you end up going after learning the ST400 turret was discontinued? Knowing how you handled the setup with your Ram and Durango could really help others facing the same challenge.

Brandon T.

1/1/2026

@JesseM I didn’t really find a good solution but we found a work around. I removed the bed rails in the inside of the bed to allow more clearance. I also set the BW hitch to the higher setting and am towing nose high but that has given me enough turning radius to back into all the spots we have stayed at. Would like to raise the back end of the camper at some point to compensate but haven’t found the best way to do that yet without adding a whole subframe.

Jesse M.

1/2/2026

@BrandonT Ok nice thanks for sharing! Good call removing the bed rails and raising the height setting on the hitch. As far as raising the back end of the camper, it can be done. The best way to do this is with a lift kit like the Correct Track Trailer Alignment and Lift Kit # RR23QX. This adds 1-1/4" of lift to a tandem axle double-eye leaf spring setup. About how much lift would you say you need to level things out?

Brandon T.

1/2/2026

@JesseM I have looked at that lift kit and it would definitely help but to be completely level it would need about 4”