Just rebuild the 5.3...
SOOO MUCH STUFF YOU CAN GET
Mine is a beast with a comp .525, no AFM, bigger ThrotBody, Airraid, new waterpump, oil pump, chain, no cats-duals with balance tube and shift kit in 4LE and royal purple in G80diff. ppv wheels tires 265x60x17's and 3.73's.
Less than 1700$...