Hanlon motorsports, but you get the whole kit, there is no sense in taking the trans apart and only fixing one blocking ring. Not to mention, it could be one of the other small parts causing the problem, this way you get eveything.
I got a kit from hanlon and the bearings wern't hardened. The roller bearings between my input and output shaft failed and ate up both shafts. I did order some gears and a shift fork from them and their prices were really good though.
Kevin