There is a company out there that makes kits like you want for the 88-98 style trucks, but I forget who and I dunno if they make the conversion kit for the 99 and up style trucks like yours.
Also, that's a lot of power. That thing has to much power for your tranny (if you have automatic) and axles. If you have an auto tranny you'll need to ditch that 4L60E for a 4L80E, and those 1/2 ton axles just aren't going to stand up to it.
285/75R16, 255/85R16, & 305/70R16 fit on a stock GM IFS fullsize 4x4 truck when on the stock 16x7 rims.