I had the same problem and same worries on my 2006. Rather than try the bolts, I got a mini grinder and opened the crack up about 1/8” wide and deep. Then filled it with JB Weld. That was last September and so far no problems or noise. If you can’t get a mini grinder in there, try cleaning the area and cover it with the JBW. I’ve also used “Gas Tank Repair” 2-part epoxy putty on heads, intake and freeze plugs So that could work for you too. It sets quickly and the heat really hardens it.My 07 Titan has a cracked exhaust manifold on the driver's side, over 200,000 milles. Any experience turning those bolts out without breaking?