ISO Qualified Mechanic. I have a 2007 Chevrolet Trailblazer with. 4.2L i6 that started knocking, had metal flakes found in the oil pan, and is now out of commission. I'm looking to go off of the advice of the shop I took it to and swap out the engine completely. Does anyone know of a decent, fairly priced, mechanic that could handle the swap and potentially warranty their work?