This seems to be a common problem, however there doesn't seem to be a common solution. I have seen some other threads in which people have this issue but no one seems to be able to decide if its a clutch problem or a shifter problem. When I am shifting into 4th or 5th at 6500-7500 rpms I am met with terrible lockout and just cant seem to get the car into gear. Im unsure if it is because the shifter is bad or if there is a clutch problem but either way I was wondering if anyone could give input on what solved the problem for them. The car already has some short throw shifter installed by previous owner but I do not know what kind but it isn't a barton or mgw. It almost feels like the drivetrain flexing at high rpm is making the shifter miss its gears. Any advice or information on why this is caused is appreciated.