I know it’s been almost a year but any updates on this truck. Flatbed looks killer!I’m a sucker for an old Cummins. Got one myself thats about to get some Carli, DOR, Fox loving. Gonna try a full swap to 4th gen steering. Shaft, box, tie rods etc… Cummins is great. Dodge… not so much …
I may have missed it, but what year is yours? If it's a 2000-2002, then the updated 4th gen tie rod bolts right on.. when they swapped the Dana 60 to the 2-piston calipers and slip-on rotors for MY2000 they changed the knuckle a bit too, and the 4th-gen tie rod is the correct stud taper and overall length to just bolt right on. I'm actually guessing that it was just an engineering update to the steering design, and then Dodge rolled forward with those same dimensions for the 3rd gen regular and 4th gen (2008+ "updated") steering on the AAM axles.
I know this won't be applicable to you, but since I'm typing.. for the 4th gen steering link to a factory 2nd gen 4-bolt box, you'll have to trim about 3/4" off the long side (tie rod side) steering link, in order to get the steering link overall length short enough to fit in the vacinity of a 2nd gen steering box & pitman arm.
If swapping 100% of the 4th gen linkage, then in order to use the pitman-arm-end steering link, you need to taper-ream the 2nd gen pitman arm (I just did all of this for a friend on the weekend). They changed the threads on the steering link from 1"-18tpi for the 1994-1999 Y-link and T-link, to 1"-16tpi for the 2003-2013 T-link.
One could also make/find an aftermarket CNC'd adjuster sleeve that has the 1"-18tpi LH threads on the axle end, and 1"-16tpi RH threads on the pitman-arm-end, to avoid having to taper ream a 2nd gen pitman arm.
When you add the 4th gen box, I presume you're talking about the 6-bolt huge one. This will require 1" spacers between it and the framerail, to make the larger box housing fit the non-notched 2nd gen frame. And I believe it needs longer bolts also, however the factory bolts might be long enough to just squeek by.
For the 6-bolt box, since it needs to stand off of the frame 1", you'll have to cut the steering link bits and additional ~1" total. I did this by cutting an additional 1/2" off the tie-rod-end, and then 1/2" off the end of the pitman-arm-end. And then to allow the steering link overall length to thread down short enough (with some room still for adjustment) I cut 1/4" off either end of the steering link adjuster sleeve.
I'm really curious to see what you do for the steering intermediate shaft into a replacement 6-bolt box. I have the PSC "2nd gen drop in" 6-bolt box, so it came with the correct box input shaft splines to receive a factory 2nd gen steering shaft, but my friend with the 1996 wants to upgrade to a parts-store factory replacement 6-bolt box, so utilizing a 4th gen intermediate shaft would be killer if that can just fit onto the 2nd gen steering column shaft.
Anywho.. sorry for the thread hijack! I just kept typing the info as it came to me haha.