I was going to drill the hole but chickened out.
I was going to do it, had the engine bay covered, hole saw ready to go but I wasn't thrilled with the hole being over the top of the PCM area. My thought at the time was "Wow...this is going to get soaked in the rain, wash, etc." So I decided not to do it.
Instead, I installed a vented cowl from Autoform. The cowl does allow heat to escape, I can see it through the windshield. At some point....there's only so many openings one can drill into their hood and what problem is that actually solving? I don't believe the GenII vipers have issues with heat not escaping from under the hood, rather, it's getting more AIRFLOW through the engine bay that's the key. I installed the Roe Front Fascia kit some time ago, and it does increase air flow at speeds above 40+mph and does help manage my engine temps. That was Mod#1 on my temperature journey.
Mod#2 was a lower temp thermostat. It helps, kind of opening a window sooner on a hot day. However, eventually with the window open sooner....it will get hot.
Mod#3 was the vented cowl. I see it working, don't know if it's actually contributing to cooler coolant temps or not. Might be helping make the interior more tolerable in idle traffic.
Mod#4 was programming the PCM with an SCT tune to change the fan turn on temps. In my case, they were changed to come on sooner than factory. Unless it's 100 degree day, my temps stay around 195ish (middle mark on the guage) tops with the way the fan comes on now. I've seen it get up to 206 degrees in 100 degree weather on a hot brutal day. I log OBD data so I know the numbers. But the new fan settings does a noticeable difference in managing the temp.
But all of it doesn't really matter is better airflow isn't making it's way through the engine. This is why I believe it's a combination of things I listed vs. drilling a 5" hole. Assuming of course, that a less hotter engine bay is the goal.
I will say that with better airflow....it seems the heat gets to the cockpit quicker, LOL, as it's forced out of the engine bay.
At some point I would like to install additonal pusher fans, like Dave6666 did, and have those come on at different settings than the stock fan or work in conjunction with the stock fan. Airflow is key, more of it.
I should also add that I run a different mix of Coolant/Distilled Water than what the factory recommends. I think I run 30% Coolant / 70% Water with some Water Wetter. But that's another topic, different discussion.
There's no silver bullet, I've learned. The Viper enginer was engineered to run within a certain temperature range.