07 classic 4.3 to nbd 5.3

[Nickadamsaaa]

I found another one a 6.0 that has everything out of an 08 2500 Will the wiring harness and everything match up Will be using both motor and trans

[Frenchy]

No. If your truck is 07 GMT800, you need a harness from an 05-07 GMT800. Let me know how it goes, no one has ever done this swap before as there is obviously no available information.