A quick compatibility check online shows Wix 46573 came out of a mid 2000s gm van. Pics of the air box look about the same also. I didn't come out
of a Duramax pickup as those air boxes are square.
I did have a round air box out of a 2 ton truck with a Duramax but I think that was a larger tube and bigger filter.
1977 Palm Beach
Green Jelly Bean
Twin Cities, Minnesota