Some impacts can put out a butt load of torque . You probably have a feel for yours but many wont . I would just recommend a good snug with an open end or to under 35 ft-lbs with Torque Wrench . An intake is 25 using same bolts .
I agree with using your arm as the torque wrench. I have broken a bell bolt trying to be within spec. 50 is a lot. Navy torque it and get in the habit of checking after shakedown.
