6.2 is a 58t so youll need to have the crank pulled and the 24t put in OR order the 58t tob24t converter (275.00)
the 6.0 needs to be a 02-07 classic thats a 24t so itll work with a nelson performance harness OR a reworked stock harness. you get a newer 6.0 thats dbw, sell that and pick up a dbc tb so it can work with your stock throttle cable.
redheartbeatbhas a lsx swap thread that is VERY helpful, or you can go to 1994 chevy 1500 progress and youll have the 58t to 24t swap help
2008 GMC CCSB 6.2/6L80e swap
Gen IV 5.3/60e swap 1994 ecsb W/T