This thread has some nice feedback, it doesn't look like the sanwa-JLF mount will fit in the injustice stick. Quoted from someone modding the stick
"Actually the mounting holes do not match, and you have to drill to widen those holes for a Sanwa, Seimitsu or Crown stick to fit. I compared the mount holes with both a flat JLF mount plate and several flat Seimitsu flat mount plates the SE, MS, RE and P-40. The VF and SS seimitsu plate will not mount.
I treat the Crown 303-FK as you would the JLF plate and widen holes for mounting. You would want longer screws with washers. See my LS-32 install guide for details.
I can't say if the mount height would be correct, as there little space inside. Do not quote me on this, but from what I can tell, you might be able to swap the Crown 303-FK's mount plate for the stock Qanba plate inside the Injustice stick.
Also if the joystick is not a Seimitsu LS-55, 56, 58, Sanwa JLF or the Qanba Clone you will have to engage in some case cutting of the bottom panel."
here is a nice picture of a mod from some member