I’ve decided on the OBX LTs with cats, for my 6.0/4L80 swap into my 01tahoe. So I went to their Website and found:

501-1307-1 cat, 2000-2005 Chevy Tahoe suburban avalanche 2/4wd 4.8l or 5.3l ls1 or ls2 (with cat)

And

501-1310-6, 1999-2005 gm trucks/suv 6.0 (including 2500 series, Hummer H2, Silverado SS, Cadillac Escalade, and GMC Denali)

Now I’ve try emailing the company twice with no reply.
I’m leaning towards the 1310-6, but just wandering what is the difference?
thanks for the help.

 

well I went with the 6.0L one. For future ref i'll post how it truns out.

 

I would guess the difference is in the ORY. The 6.0 and 2500 trucks have a different setup mounting it to the cat back.