LS ECU is best mounted where ?

[A1971Blazer]

Many factory vehicles have the ECU mounted under the hood.
There is limited room under the dash especially if you are adding AC, either factory or aftermarket.
I chose to mount mine to the back side of the core support along with a custom load center for the wiring harness.
I also made a custom cover for the bulkhead connector to hide the forward harness.
It's not a daily driver and won't be in the rain unless of course I get caught in a rain shower while I'm out in it.
2002 LS1 from a TransAm WS6
I used a factory GM mounting bracket and I have a cloned PCM just in case...
I can easily remove and replace it in 15 minutes.