Can't help you with the distance amigo, but it sounds like your overall length of the pin is too long, causing the clutch to still be partially 'disengaged' even when the lever's released. I'd screw it a turn or several into the lever and away from the boot.
I bet you have it pretty close, which is why it only slips at 5K +
I bet you have it pretty close, which is why it only slips at 5K +