Turbo and heat shield and, and, and, on my 2000 H-1

[MickerH-1]

FOund out through AMerican General that my repair is covered through 70k as an emission system warranty repair. I informed dealer of this (Fitzpatrick Chevrolet HUMMER in Concord Ca.) of this fact, they are fixing it under warranty. My question was why was a book time job of 3.5 Hrs for the repair costing me $1,600 if the inlet pipe and heat shield were less than $200 at other dealerships. My figh now is that the dealer broke off the bolt and now the head needs to be removed and fixed. The factory warranty warrants the exhaust manifold and "related parts". The dealer showed me an exhaust manifold bolt that had cracked 3/4 of the way through and when they put a wrench on it,it broke. HUMMER is saying they don't warrant the bolts. Isn't bolts a "related item" if the manifold isn't held on magnetically? Maybe it was broken at the factory when it was assembled or was defective. I may have to arbitrate. Any ideas?