Kobelco 6-71 Hi Helix rotors?

Did Kobelco or any other blower manufacturer ever make a hi helix rotor set for the Kobelco 6-71?

I realize that the 6-71 is predominately used in the nostalgia racing class, which only allows the use of standard helix rotors. And I also realize that because of this, the demand to produce a hi helix 6-71 is not there for the manufacturers.

The reason I ask this is that I have a pulling tractor with a Kobelco 6-71 with K11 rotors. Our rules, which are state level, allow a small block with a 6-71. There is nothing that states any limitations on rotor design, just maximum engine cubic inches as well as blower OD. In other regions, this same class is allowed 8-71s, which opens up the doors for several current options for standard or hi helix blowers.

If possible, I would like to have the option of upgrading this blower.