Hoping someone can help me out,
I have a 03 rcsb that was a 4.3 truck, the swap is not my issue.
My issue is what I need to do orcwhat options I have as far as pcm and harness.
I'm wanting to pull all my engine trans from my turbo 5.3 ecsb and out into my rcsb.
The ecsb is a 2001

Basically I'm wanting to use my 01 5.3 & pcm in a 03 truck.. ???
I've searched and searched and can't seem to find any definitive info

 

If I recall
the 99-02 pcm has 512kb memory
the 03 up has 1 mb memory (serial communications in vehicle)

i dont think it will work like you want it to- I wondered this also

 

Yea, I'm wanting to use my 02 5.3,harness and pcm. As pcm is already licensed on 3 bar OS. So I'm basically thinking I just need to mod harness and run as a stand alone.i think that's my only option from what I can gather.

 

Please can anyone help, hardly believe I'm first to do this...

 

You still need a 1MB PCM from an 03-07 classic if you want the vehicle to work correctly.

 

you could always swap the dash and bcm with related harnesses from your 01 donor. seems like itd be more hassle than its worth though.

 

So if I use 03 harness and pcm, will all harness plugs be correct it will I need to do some repinning?

 

With my 02 engine that is

 

I have a 03 pcm and v6 harness, could I simply wire up the other to injectors and be good to go?