I think the only vehicles that the LQ9 came in were the Caddy's and SS Silvo but could be wrong.
Weight wise the engines are nearly identical in block ( iron ) and heads. The reciprocating mass is larger on the 6.0L but have less cylinder meat. Probably too close to notice a difference.

 

you have the oil cooler lines to deal with. I got a denali radiator. The radiator is bigger so u need to get denali fan cover.

 

i made 360 ft lbs on my first full throttle pass with 6.0 swap.