4.8 to ls1 2001 Silverado knock HELP!

[Turbodart]

I have a ls1 installed in a 01 Silverado.My question is could the aluminum block require a change in the knock sensitivity settings form the 4.8 iron block?i am experiencing knock in 2000 to 3500 rpm areas at .65gm and up cyl air consistently. Afr and timing changes don't seem to help.
Mods include 220*/228*cam,trunnions ,springs, kooks headers, catless mid pipes tru duals,cold air. Trailblazer converter, and running truck intake. Any help is appreciated thanks.

[cobaltssoverbooster]

depends on the density of the cast block and the aluminum block. auditory signal for both is around 0.250 inches per micro second.

[gallegos276]

Have you had suspension work done to your vehicle. I had lowered Silverado did the same thing and it was very clear there no knock. Add higher octane and lower timing to help rule it out and make sure your - +1to5 on your fueling chart in that area while your scanning.

[CBraden]

I have a ls1 installed in a 01 Silverado.My question is could the aluminum block require a change in the knock sensitivity settings form the 4.8 iron block?i am experiencing knock in 2000 to 3500 rpm areas at .65gm and up cyl air consistently. Afr and timing changes don't seem to help.
Mods include 220*/228*cam,trunnions ,springs, kooks headers, catless mid pipes tru duals,cold air. Trailblazer converter, and running truck intake. Any help is appreciated thanks.

Did you get this figured out? I am about to install a conversion to an aluminum block, so this is very pertinent to my interests.

Thanks