Kendrarachel

Hi Everyone,
My name is Kendra. I have a 1997 C1500 exrended cab with a 4.3 vortec. I am trying to swap to a 5.3 from a 2000. I wanted to know if anyone could tell me everything I need from the 2000. I know I'll need new motor mounts. I don't think the one from the 2000 will bolt in my 97'. Fuel lines, tranmission lines, pcm and wiring harness, radiator ect. Is anything interchangeable? Does anyone know if my tranmission will bolt up or will mime even work with the new PCM and wiring harness? Will the sending unit and fuel pump work? Instrument cluster? Rear end? I know the 4.3 are a straight swap from blazers tranmission and all up to 01' but correct me if I am wrong the 5.3 in 2000 was changed correct? Any help would be great as soon as possible and I know it doesn't make much since to do this but I was gave this motor and tranny from my buddies rear-ended chevy and I'm giving my truck to my sun when he's 16 we just did a paint job and the interior and I think it will be a good start for him.