I couldnt tell ya. I dont mess with the torque wrench there. I use a 1/4 ratchet,w/ extension,( sitting facing the rear of the bike on the passengers side, ritght hand holding the tools) a rather short one, & put my thumb on the head of the ratchet & with the handle across the palm to the open fingers, si close the fingers, gently. Never grip the ratchet & use the arm. Go slow. YOull feel the thing start to snug up, because youre tightening it in a way that isnt stronger than it is. If you grabbed a 1/2 ratchet & just started cranking on it with both hands, youd never even feel it come tight before it was stripped. This way, you can feel it go from loose, to just snug to offering more & more resistance. Dont go to the place where your thumb is on the head of the ratchet & your fingers are open but curled & gripping & use that arm. Just use your hand & youll get it tight enough.

I knew I forgot some details. Rowboat is exactly right. If you feel the bolt "Land" & start clamping steel to steel parts, your compression gasket is 100% compressed & youre gonna be needin another one, Id say when it gets loose again. & Yup, if you own a motorcycle, you Need to own a jug of antisieze. Much better to be snugging those up once in a while than realize theyre corroded in place on the day you want to pull the header.

FWIW, the book says 13-20 ft-lbs for those bolts.

I use 13 ft-lbs, on a cold engine.