I found that my hand position on the shift knob made a big difference. With my hand on top, I sometimes "ground" it getting into 5th; even 3rd was a problem. Now with my hand on the side, holding it like I would a hammer, it's easier to shove it diagonally into 5th. But I do occasionally have problems going from 5th to 6th.

getting the gear in is easy, everytime i do it over 6k rev it grinds b4 it goes in

Try using the clutch.

Seriously, you're probably hurrying the shift - if you hold the clutch conciously down and shift deliberately, does it still grind? My guess is not. Take a hair more time shifting.

At first I thought this thread was about the car show, not the transmission.. LOL!

It's either your method of shifting or maybe something's wrong w/the syncho.

I agree. At least for me, shifting into 5th requires a somewhat unnatural motion, and I have to do it very deliberately. However, I haven't miss-shifted into 3rd yet. Going from 5th to 6th also requires some deliberation, but not as much.

I found that the best way to shift from 5th to 6th is to grab the shifter as if you were emptying a can of soda. Then, as you pull it down and away it goes nice and smooth.