Ya, I went with brass bushing so I wouldn't have to do this again anytime soon. Were you pleased with Tulsa Spring cost/time? Do you know if they have the right equipment to do both top and bottom bushings at the same time to keep the axial line straight for the new kingpin?
If you don't keep them greased you will need to do it again, the nylon is suppose to not wear as bad under miss maintence. Also check the hole in the I beam for slop. I had to heat and beat mine closed and redrill and team out the I beam the last time I had mine apart. Tulsa spring does a lot of big truck stuff that use solid front axle so I would assume they had the correct tools. Mine came out good and fit like a glove. I did all this when converted to disk brakes.