I too have been thinking of doing efans...
So far in my research & slow moving plans, this is what I found...
I've got PCM4L to tune out the fans code on both the 5.3 and the 4.2.
I was going to buy
THIS fan set. Which I'm glad to see is the same PN as posted here already. Not the cheapest though.
My questions for those are;
1) Do they just drop in the 5.3l Envoy bay?
2) Do they just drop in the 4.2 TB bay?
3) Are these what they call the LS1 fans?
As for controlling them on the 5.3 Envoy, I was going to get one of
these kits from PCM4L. I have no clue if that will work on the 4.2 though. I'm still researching myself.
I'm so glad that I'm not doing the research on my own now....