GTX/GTR Gearbox & Miata LSD

[akinat90]

I am trying to locate one of these boxes, used but in good condition. I have a JDM Familia R4 i.e. 4WD a/t that i am doing aconversion with. I have already put in the Mazdaspeed engine but want to run more HP than stock. The automatic tranny cannot take the torque so i want to do the manual conversion as well as change my rear diff from an open one to a LSD.
Thanks for the help