I picked up a set of ’82 Kawasaki GPz750 (one-year-only KZ750R) steering clamps and steering stem for $24. Instead of the GS700ES steering stem’s 30×52 lower bearing, the GPz uses the same 28mm ID bearing I need to fit the Aermacchi frame. If it could work, it would simplify machining, and move the extra length of the steering stem above the steering tube of the frame, rather than below it (helping hide the extra length of the forks).
Unfortunately, I mistakenly thought that the ’82 GPz750 used 37mm forks. Nope. While the ’83–’85 GPz750 “Uni-Trak” models did use the same 37mm fork diameter as my Suzuki forks, the ’82-only “R-model” was equipped with 36mm forks. (Over the next to years this twin-shock chassis would morph into the 1983 KZ750-L3 and 1984 KZ700-A1 standard models.)
Another factor I had not considered, though, is that the Kawasaki triple clamps have more offset, reducing the overall trail by about a half-inch or so. It was a cheap purchase, so it’s no big deal that I’m sticking with what I had. I guess have an additional option for some future project.