airbox
#2
TECH Fanatic
Junkyard or someone parting out their ride would be the cheapest.
Then there's GMpartsdirect.com - can just search for this part number :
LS1 upper radiator support (holds the air filter support bracket / housing) = 25170361
Then there's GMpartsdirect.com - can just search for this part number :
LS1 upper radiator support (holds the air filter support bracket / housing) = 25170361