Do you happen to know the torque on those flanges?
The torqueing process is not as straight-forward as you might think . . . Note: this is for the installation of the head pipe as from the HD Service Manual. If you are after the final torque setting for the Exhaust flange Nuts, see # 1 and #2 below.
Once the pipes are on the bike and the flange nuts are loosely attached the sequence and torque settings are as follows:
1. First the Rear Cylinder - tighten the bottom nut to 9-18 in-lbs, then tighten the the top nut to 100-120 in-lbs. Go back and final tighten the bottom nut to 100-120 in-lbs.
2. Then the Front Cylinder - tighten the top nut to 9-18 in-lbs, then tighten the bottom nut to 100-120 in-lbs. Go back and tighten the top nut to 100-120 in-lbs.
3. Tighten the flange locknut (where the rear of the pipe attaches to the frame) to 20-25 ft-lbs.
4. Next the crossover pipe clamp is also torqued to 20-25 ft-lbs
5. The crossover bracket bolt is then tightened to 14-18 ft-lbs.
6. Attach the heat shields - the clamp screws are tightened to 20-40 in-lbs.