GMC Sierra Peace, mercy, and blessings of God be upon you. I am offering an LS1 engine with a 5.3 capacity. The only modifications are to the oil pump from Milodon to avoid lifter problems and to extend the engine's life... The engine is very clean, and the buyer has the right to inspect it. The car currently has 340,000 miles and is very clean, guaranteed not to have been opened before. The engine's front cover was only opened for maintenance of consumables.