PCM location - how protected does it need to be?

[WorldsCrappiestTruck]

My first Gen3 LS I put the PCM behind the ashtray area, because I wanted a very clean engine bay - all the wiring is tucked and runs through a single 2” grommet in the firewall to the PCM. I LOVE how it looks under hood, less how it looks on the interior as you can see it up under the dash, and now I really dislike it because it’s going to really limit real estate for adding HVAC which I didn’t do up front (mistake - just wanted to get it going).

My current Gen3 I’d like to put the PCM under hood but hide it nicely. Maybe in the radiator support area on the lower drivers side? From the factory, these units were under the hood, strapped to a plastic mount and pretty much exposed to road grime, heat etc in the engine bay.

Is it okay to put it in a sealed box to “pretty” up an install, or should it have cooling airflow? Can you put it down in the water & dirt & grime as long as the unused pins have been silicone’d shut? Can it be protected from water, but should still have airflow around it?


Looking for creative recommendations to where you can “hide” a gen3 PCM underhood. Thx.