Clutch rattling? Lose starter maybe?

If you are talking about the kind of grinding, rattley sound near the end, it sounds kinda like your throwout bearing is going out on you or somehow having a problem rotating when it contacts the clutch fingers; it does not contact the clutch or rotate until you put some pressure on it which you are doing by resting your foot on or pushing in the clucth pedal.

It is almost certainly in the throwout bearing area. I have not had one of these particular models apart but sometimes clutch forks gets misalinged on the throwout bearing slot or surface on which it rides, and can cause problems. Ths might have gotten cocked or misaligned in the header install process.

Take off the boot and look, and make sure the fork is in right, but if there is nothing obvious there, I would pull the trannie and bell housing. The throwout bearing can already be seized and it will make exactly this kind of sound as it rubs against the clutch fingers rather than turning with the clutch when it makes contact.

The other Mark