The best ones I'm aware of are Redhead steering gearboxes. They essentially blueprint their rebuilds, including flame-spraying or replacing shafts, custom fitting bearings, worms & sectors, and super polishing seal surfaces. They'll even install needle bearings where there were no bearings.
They used to describe their rebuild processes as including several tolerance levels, including a very high performance custom level of rebuild intended for vehicles like race cars and police interceptors. I'm not sure whether that ever got into different ratios, though they do say they specialize in rebuilding quick ratio steering gearboxes for pick-ups and SUVs, including Dodge Dakota from 1986 up... Dakotas and B-Vans shared many parts over their production runs. Perhaps they're compatible?
The overarching goal was to reduce lost motion and indecision in steering though, so even if there's no applicable quick ratio gearbox, perhaps that interceptor level rebuild would suit you?
They do have a page where you can ask for quotes on custom rebuilds - from their home page it's under Rebuilding > Rebuild My Gear
https://redheadsteeringgears.com/rr-my-gear-formThe form says to call if you have any questions, so that may be your ticket. Their number is 800-808-1148. They're in Auburn Washington, so they're in the Pacific time zone.
You may also want to closely scrutinize your steering coupler. It can easily be far worse than the gearbox.