I make these replacement kits for all Norton Featherbed frames (also used in Triton / NorBSA / NorVin builds) to replace the wimpy 1/2" or 5/8" swingarm pivot bolts, and troublesome infernal "rubberlastic" bushings once and for all.
The spindles are turned from high grade 3/4" steel with bolt-up security plates (stainless steel hardware). Bushings are high quality sintered bronze, recessed for viton o-rings to retain the lube, and include sintered bronze thrust bushings on the outer ends.
All that is required is to drill out the existing swingarm pivot bolt holes to 3/4", then mark and drill (4) 1/4" holes in the frame webs. Then, drill and tap a 1/4" hole in the top of the swingarm tube to allow lube filling. The hardest part is typically removing the *&^%$#@ old metalastic bushes! Then, simply press in or draw in the new bushings with an 18" piece of 3/8" allthread rod with 2 nuts and washers.
The result is absolutely crisp, stable rear suspension with no more fuss every time you try to remove the swingarm.