rickdlance swapped LLY heads on his LBY, can't do with 2001/2 only 2003+ because of Computer electronics stuff. saw write up on conversion while back. pretty much engine components go back and forth, just improvements for power with age.
02 silverado cc/sb LS D/A,
hypertech III, SuperDiesel manifold, Kennedy guages. 265/75-16 2WD, 4inch exhaust, mouthpiece ported