in 2015 we were in email correspondence about the known problem that 4th gear cannot be engaged silently under load at the OS Giken close ratio modified transmission. the synchronizing ring is probably worn. Do you still have your reinforced parts? you told me, that you turned off and hardened the synchronizer rings from the newer z32 gearbox, so it will withstand high-power torque.
Hi mikec, i saw your post on twinturbo.net about a worn slide hub in combination with the osgiken close ratio kit. i also have this kit and the problems with the 4th gear. do you still have the modified slide hubs to repair the gearbox and selling these? price? cheers chris