Hi, I'm looking for a 5.1 ratio or similar to fit an FD rear end. Is there such a thing, and if so, where to buy?

I heard Mazdaspeed offer one, but have not been able to confirm. I also know Mazda pickup ratios fit, but the lowest I can find is 4.77.

Any suggestions would be much appreciated.

 

4.77 is the shortest read end I have ever head of for the FD

 

the pickup gears fit the NA rear ends, the FD shares with the Rx8

 

Mazda Motorsports part number for RX-8 5.12:
0000-02-8601 $1500

Mazdatrix, same exact price:
http://www.mazdatrix.com/8-Diff.htm

Their part number reordered back to Mazda part number turns into:
PA28-27-110Y-05

Entering this in Mazda Motorsports search and came up with the same price as all above but no description available.