2000 GMC Sierra 1500 5.3L V8 - Changing passenger exhaust manifold

[Schugg]

my friends exhaust manifold needs replaced and just by looking at it, it doesn't look like a problem, but every shop he goes to doesn't want to do it, is there something i cant see that makes it a lot harder than it looks? i told him i would look into doing it for him, but if there is a reason i shouldnt let me know

[WHT_EP3]

Aluminum heads + rusty bolts = stripped threads + confined area to heli-coil repair is a No Bueno