I've seen someone drill a hole in the center of the column mounting plate under the dash. This allows you to push in the column an inch after loosening bolts in engine bay but your left with two mounting bolts as apposed to 4 under the dash.
Its a direct swap, there's isn't one for K but it should fit a K, I don't know what 14 spline is about, the one I picked up had a 26 spline. If you want to do this swap you also need gm bolt Part #11610555
Sounds like wire going to senidng unit is cut or gauge cluster printed circuit is messed up. I would look up the temp wire on the 18 pin and see if you get any continuity
You dont want to use Dakota Digital? I used Dakota Digital on my 90 Burb i just connect the vss signal wire from 18 pin connector to my dakota digital speed snd on the digital box worked fine after calibration
On a side note an alternative to XJ shaft is a steering shaft from a c3500 88-94 is the best of both worlds you eliminate the rag joint but retain the crossbolt, installed one in my 90 Burb
On a side note if anyone is looking to reduce emission exposure from their vehicle a working PCV system is key. Engine blow-by can be worse than anything coming out of tail pipe, even catless.
Do you still have the shroud that covers the rear ac, the tube just slips onto the passenger side corner of the shroud, you should see a round protrusion on the corner of the shroud