George Parker built one. That is what I have in my Modified Roadster. I don't think he sold very many. He ran one in his Streamliner, so it is out there somewhere. There is the one in my modified, and Doug Robinson had bought one, which he never used. They were a Quick Change unit with either a 1.5-1 or 1-1 Ring and pinion. I really wish there was room for a 2-1 Ring and Pinion but so far I have not been able to locate any that will fit.
The other one that has been built is the Winters Extremeliner that is available with a 2-1 Ring and pinion. It takes different Quick Change gears than the standard 10 spline.
It would be interesting to ask Winters if they could put the 2-1 Ring and pinion in their Banjo Style full size rearend.
Strasburgs (sp) make a LSR quickchange, but I don't know anything about it.
I am sure there are others but these are a few.
Tom G.