Mikesprojects

I am in the process of rebuilding a 2004 5.3 LM7 from a Silverado that I bought from the junkyard. The idea was to then buy a really nice 2004 Silverado or Sierra in great condition except with a blown motor. I want to just pull the bad motor and drop the good one with no modifications or tuning necessary.
The problem- finding a 2004 Silverado or Sierra with a blown motor.
The Question- what range of years of these two GM trucks would be compatible with my motor? With the exact same wiring harnesses and everything else?
Thanks for reading.

Mikesprojects

In other words, could I drop the 2004 LM7 into a 2007 Silverado 1500 with everything matching up? Or would I have to swap some of the newer components onto the older engine before I can drop it?
Do you know of any years that the 2004 LM7 would definitely fit directly into without swapping components?

gagliano7

I am pretty sure from 1999-2007. Any one that has the gen III engine the LM7 will be a direct fit.

JakeFusion

iTrader: (7)

Everything would swap 99-07. TB changed in 03 to drive by wire, but the short block would work in any of them.

Mikesprojects

So then I will be able to buy any 2003 - 2007 1500 Silverado or Sierra that came with the 5.3, pull the old motor out and drop my rebuilt 5.3 in it AND:
The wiring harness will match
The PCM/computer will be compatible (didn't 2007 have flex fuel option?)

Mike_hawk

The easiest solution and what I think most are suggesting is finding a vehicle that didn't have VVT or AFM and only replace the block and heads, leaving the vehicles wiring harness/intake to avoid changing anything else.

Mikesprojects

Light bulb!!! I'm sure inexperience is why I had not yet considered this option...
Thank you for clearing it up mike_hawk!

gagliano7

Jut use the new long block and transfer all your sensors and manifolds over from your old motor and use your original wiring harness and pcm and fire her up.