My 04 rcsb 4x4

Hey there I'm new to the forum I have an 04 rcsb 4x4 roller had a 5.3. The only power plant available to me was from an 08 5.3 as well I have the original harnesses from both and ecu and fuse blocks how do I wire this to make it work help needed badly

welcome to the site.
GenIII to GenIV is quite an involved ordeal; good luck.
if you dig around, there are a number of write-ups that detail all the things (like reluctor differences, knock sensor wiring, etc).